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Mammalian distal humerus fossils from eastern Montana, USA with implications for the Cretaceous-Paleogene mass extinction and the adaptive radiation of placentals

Lauren B. DeBey and Gregory P. Wilson

Plain Language Abstract

The Cretaceous-Paleogene mass extinction represents among the most significant events in mammalian history. Conventional understanding of this event suggests that with the extinction of non-avian dinosaurs, mammals inherited the earth and quickly diversified to fill ecological niches (e.g., large body size, diverse locomotor modes and feeding ecologies) previously unoccupied by mammals. Whereas most studies of this event have focused on fossil teeth, this study uses upper forelimb (humeri) fossils from the well-sampled and well-studied Cretaceous and Paleogene deposits in eastern Montana to assess the diversity of mammalian body sizes and locomotor modes. The results of our analyses show 1) a change in the composition of mammal faunas across the K-Pg boundary, from ones dominated by the more archaic group called multituberculates to ones largely made up of the more modern eutherian mammals; 2) changes in body size, from an initial decrease across the K-Pg boundary, to an increase in body size in less than 1 million years; and 3) a greater locomotor diversity among K-Pg mammals than previously recognized, including climbing, digging, scampering, and ground-dwelling forms. This study expands our view of the ecology of these early mammals and our basis for testing ecological hypotheses of the K-Pg mass extinction and recovery.

Resumen en Español

Fósiles de húmeros distales de mamíferos del este de Montana, EE. UU., con implicaciones sobre la extinción en masa del Cretácico-Paleógeno y la radiación adaptativa de los placentados

Los restos postcraneales de mamíferos del Cretácico-Paleógeno (K-Pg) ofrecen información sobre la riqueza, el tamaño corporal y la ecología locomotora que complementan los patrones mostrados por conjuntos dentales bien representados. Aquí, describimos y asignamos morfotipo a 50 humeros distales de asociaciones de edad Lancianense–Puercaniense del este de Montana. Utilizando el análisis morfométrico geométrico de una muestra taxonómicamente amplia de húmeros de terios actuales de cuerpos pequeños con diversos modos de locomoción, restringimos las inferencias locomotrices de algunos morfotipos. Usamos esta base de datos para evaluar preliminarmente la diversidad del tamaño corporal y locomotor a través del límite K-Pg.

Los siete morfotipos de húmeros del Lancianense incluyen los multituberculados ?Mesodma sp., ?Cimolodon nitidus, y ?Meniscoessus robustus y el metaterio ?Didelphodon vorax. La riqueza de morfotipos disminuyó a cuatro o cinco a través del límite K-Pg y aumentó en el Puercaniense tardío a seis morfotipos, en su mayoría euterios. Los morfotipos del Puercaniense incluyen el multituberculado ?Stygimys kuszmauli, el primate "plesiadapiforme" ?Purgatorius, ungulados arcaicos pequeños y grandes, un posible paleoríctido y un gran euterio. Los datos del tamaño del húmero implican una disminución en el tamaño del cuerpo a través del límite K-Pg, seguido de un aumento en el Puercaniense tardío, una tendencia consistente con lo que indica el registro fósil dental. El análisis morfométrico geométrico y la morfología funcional indican una mayor diversidad locomotora entre los mamíferos del K-Pg que la previamente reconocida: inferimos que la mayoría de las multituberculados del Lancianense y Puercaniense eran arbóreos; los euterios del Lancianense eran arbóreos o semifosoriales; los paleoríctidos del Puercaniense temprano eran de semifosoriales y el pequeño ungulado arcaico era terrestre; y el primate "plesiadapiforme" del Puercaniense tardío era arbóreo y el gran ungulado arcaico era de escansorial. Tomados en conjunto, estos resultados preliminares amplían nuestra comprensión de los mamíferos del K-Pg y nuestra base para probar las hipótesis ecológicas de la extinción en masa y recuperación para el límite K-Pg.

Palabras clave: Mammalia; restos postcraneales; húmero; extinción en masa; Cretácico-Paleógeno; morfometría geométrica.

 

Traducción: Enrique Peñalver (Sociedad Española de Paleontología)

Résumé en Français

in progress

Translator: Antoine Souron

Deutsche Zusammenfassung

Distale Humerus-Fossilien von Säugetieren aus Ostmontana, USA mit Auswirkungen auf das Kreide-Paläogen Massenaussterbeereignis und die adaptive Radiation der Plazentatiere

Postcraniales Material von Säugetieren aus dem Kreide-Paläogen (K-Pg) Übergangsbereich bietet Einblicke in die Vielfältigkeit, Größe und Bewegungsökologie und ergänzt die Modelle aus den Proben der Zahn-Assemblagen. Hier beschreiben und morphotypisieren wird 50 distale Humeri aus Assemblagen (Lancianium – Puercanium) von Ostmontana. Indem wir eine geometrisch-morphometrische Analyse einer taxonomisch breitgefächerten Probe von Humeri von heutigen kleinen Theria mit diversen Fortbewegungsweisen anwenden, schränken wir Fortbewegungsinferenzen einiger Morphotypen ein. Wir benutzen diese Datenbank um die vorläufige Größe und Fortbewegungsdiversität an der K-Pg Grenze zu bestimmen.

Die sieben Humerus Morphotypen aus dem Lancianium beinhalten die Multituberculaten Mesodma sp., ?Cimolodon nitidus und ?Meniscoessus robustus und der Metatheriane ?Didelphodon vorax. Die Morphotypen-Vielfalt nahm an der K-Pg Grenze auf vier oder fünf ab und stieg im späten Puercanium wieder auf sechs Morphotypen, meist Eutheria, an. Morphotypen aus dem Puercanium beinhalten den Multituberculaten ?Stygimys kuszmauli, den "plesiadapiformen" Primaten ?Purgatorius, kleine und große archaische Ungulaten, einen möglichen Palaeoryctiden und eine sehr großes Plazentatier. Die Daten zur Humerusgröße implizieren eine Abnahme der Körpergröße an der K-Pg Grenze, gefolgt von einer Zunahme im späten Puercanium, ein Trend, der mit dem fossilen Zahnnachweis übereinstimmt. Die Geometrisch-morphometrische Analyse und die Funktionsmorphologie deuten auf vielfältigere Fortbewegunsgweisen an der K-Pg Grenze hin als bisher erkannt war: wir folgern, dass die meisten Multituberculaten aus dem Lancianium und Puercanium aboreal waren; das Plazentatier aus dem Lancianium war aboreal oder semifossorial; der frühe Palaeoryctide aus dem Puercanium war semifossorial und der kleine archaische Ungulate war terrestrisch; der "plesiadapiforme" Primat aus dem späten Puercanium war arboreal und der große archaische Ungulate war scansorisch. Zusammengenommen erweitern diese vorläufigen Ergebnisse unser Wissen über die K-Pg Säugetiere und unsere Basis an Tests ökologischer Hypothesen zum K-Pg Massenaussterbeereignis und zur Erholung danach.

Schlüsselwörter: Mammalia; Postcrania; Humerus; Aussterbeereignis; Kreide-Paläogen; geometrische Morphometrie

Translator: Eva Gebauer

Arabic

Translator: Ashraf M.T. Elewa

 

 

APPENDIX 1.

Localities containing specimens used in this study. Locality numbers follow the system of each institution; those beginning with “V” are UCMP localities; those beginning with “C” are UWBM localities. All localities are in Montana except for V5620, which is in Wyoming. Abbreviations: Fm, formation; La, Lancian; n, number of specimens from the locality; Pu1, Puercan 1; Pu3, Puercan 3.

Loc. Number Locality NAme County Fm Biozone n
C0338 Bug Creek A McCone Hell Creek mixed 2
C1115 Celeste's Magnificent Microsite Garfield Hell Creek Lancian 1
C1163 MacDonald Garfield Tullock Pu3 1
C1521 Wake Up Garfield Hell Creek Lancian 1
C1845 Bug Creek McCone Hell Creek mixed 1
V5620 Lull 2 Niobrara Lance Lancian 4
V65127 Bug Creek Anthills General McCone Hell Creek mixed 11
V70201 Bug Creek Anthills C McCone Hell Creek mixed 4
V70209 Bug Creek W McCone Hell Creek mixed 4
V71203 Harbicht Hill 1 McCone Hell Creek mixed 1
V72129 Garbani 04-Nw-S Level 1 Garfield Tullock Pu3 1
V72207 Windy Hill Garfield Hell Creek Lancian 2
V73087 Flat Creek 5 Garfield Hell Creek Lancian 1
V73097 Brownie Butte Garfield Hell Creek Lancian 1
V74111 Worm Coulee 1 Garfield Tullock Pu1 3
V74122 Biscuit Springs Garfield Tullock Pu3 1
V74124 Yellow Sand Hill 2 Garfield Tullock Pu3 1
V84162 Sand Cave Garfield Hell Creek Pu1 1
V84193 Z-Line Quarry McCone Hell Creek Pu1 1
V85092 Kmark II McCone Hell Creek Lancian 1
V87001 O’Connor Site Fallon Hell Creek Lancian 1
V88007 Spigot Bottle Carter Hell Creek Lancian 1
V91065 Capping Channel Garfield Tullock Pu1 1
V93169 Anne’s Beast Garfield Hell Creek Lancian 1
V99438 Garbani Sandy Channel Garfield Tullock Pu3 3

APPENDIX 2.

Histograms illustrating the number of multituberculate (1) and therian (2) specimens in each biozone. Abbreviations: BCA, Bug Creek Anthills mixed-age assemblage; La, Lancian; Pu1, early Puercan; Pu3; middle-late Puercan. See text for morphotype details.

appendix 2

 

APPENDIX 3.

Comparative multituberculate distal humeri used in this study. We follow the convention of Krause and Jenkins (1983) with regards to prefacing unassociated attributions with a query (e.g., for isolated material). Age data for Late Cretaceous and Paleogene North American taxa are given as NALMAs, respectively; ages of Asian taxa are given as geologic stages. Specimens from the Bug Creek Anthills localities (e.g., Deischl 1964; Krause and Jenkins 1983) are given a “Lancian-Pu1 mixed” age. All families are in the Infraorder Cimolodonta. See text for museum abbreviations.

Specimen Number Taxon NAme Family Age Location Reference
AMNH 77175 ?Mesodma primaeva Neoplagaiulacidae Judithian North America Sahni, 1972
AMNH 3011a ?Meniscoessus conquistus Cimolomyidae Lancian North America Cope, 1884; Krause and Jenkins, 1983
YPM 10612a ?Meniscoessus robustus (formerly Dipriodon lunatus) Cimolomyidae Lancian North America Marsh, 1889; Krause and Jenkins, 1983
MCZ 20786-20789 ?Mesodma sp. Neoplagaiulacidae Lancian-Pu1 mixed North America Krause and Jenkins, 1983
UMVP 1405 ?Mesodma formosa Neoplagaiulacidae Lancian-Pu1 mixed North America Deischl,1964
UMVP 1403, 1406 ?Mesodma thompsoni Neoplagaiulacidae Lancian-Pu1 mixed North America Deischl,1964
UMVP 1404 ?Cimexomys minor Neoplagaiulacidae Lancian-Pu1 mixed North America Deischl,1964
UMVP 1407 ?Stygimys kuszmauli Eucosmodontidae Lancian-Pu1 mixed North America Deischl,1964; Krause and Jenkins, 1983
UA 11994 ?Stygimys kuszmauli Eucosmodontidae Lancian-Pu1 mixed North America Krause and Jenkins, 1983
MCZ 19529 ?Catopsalis Taeniolabididae Lancian-Pu1 mixed North America Jenkins, 1973
AMNH 3036 ?Taeniolabis taoensis Taeniolabididae Puercan North America Sloan, 1981
Cope 1884: Figure 4b Taeniolabis taoensis (formerly Polymastodon taoensis) Taeniolabididae Puercan North America Cope, 1884
IVPP V8408, V9051 ?Lambdopsalis bulla Taeniolabididae Late Paleocene Asia Kielan-Jaworowska and Qi, 1990
USNM 9735 ?Ptilodus montanus Ptilodontidae Torrejonian North America Krause and Jenkins, 1983
USNM 6076 Ptilodus montanus Ptilodontidae Torrejonian North America Gidley, 1909; Krause and Jenkins, 1983
UA 9001 Ptilodus kummae Ptilodontidae Tiffanian North America Krause and Jenkins, 1983
UA 11300 ?Ptilodus kummae Ptilodontidae Tiffanian North America Krause and Jenkins, 1983
UALVP 42816 Microcosmodon conus Microcosmodontidae Tiffanian North America Fox, 2005
GISPS 8-2 PST Tugrigbaatar saichanensis Djadochtatheriidae Campanian Asia Kielan-Jaworowska and Dashzeveg, 1978
PSS-MAE 103 Kryptobaatar dashzevegi Djadochtatheriidae Campanian Asia Sereno 2006
PM 120/107 Catopsbaatar catopsaloides Djadochtatheriidae Campanian Asia Hurum and Kielan-Jaworowska, 2008
URBAC 03-076 Multituberculata   Turonian Asia Chester et al., 2010
AMNH 118267 Multituberculata   Lancian-Pu1 mixed North America Kielan-Jaworowska and Gambaryan, 1994

 

APPENDIX 4.

Comparative therian fossils specimens used in this study. List of fossil specimens used for comparative study. We follow the convention of Krause and Jenkins with regards to prefacing unassociated attributions with a query (e.g., for isolated material). Age data for Late Cretaceous and Paleogene North and South American taxa are given as NALMAs and SALMAs, respectively; ages of European taxa are given as geologic stages. Specimens from the Bug Creek Anthills localities (e.g., Szalay and Dagosto, 1980; Boyer et al., 2010) are given a “Lancian-Pu1 mixed” age. See text for museum abbreviations.

Specimen Number Taxon Name Higher Taxon Family Age Location References
Marsh,1889: Plate V, figs. 5-6 Didelphodon vorax Didelphimorphia Stagodontidae Lancian North America Marsh,1889
MHNC 1249 Mayulestes ferox Didelphimorphia Mayulestidae Tiupampan South America Muizon, 1998
YPFB 6105, 6106, 6110, 6111 Pucadelphys andinus Didelphimorphia Didelphidae Tiupampan South America Marshall et al., 1995
AMNH 118456 ?Procerberus formicarum   Cimolestidae Lancian-Pu1 mixed North America Boyer et al., 2010
UMVP 1837 ?Procerberus formicarum   Cimolestidae Lancian-Pu1 mixed North America Szalay and Dagosto, 1980
UM 88105 ?Prodiacodon tauricinerei Leptictida Leptictidae Wasatchian North America Rose, 1999
AMNH 16614 Protoselene opisthacus archaic ungulate Hyopsodontidae Torrejonian North America Matthew, 1937
NMMNH P-20949 Tetraclaenodon puercensis archaic ungulate Phenacodontidae Torrejonian North America Kondrashov and Lucas, 2012
AMNH 119994 ?Protungulatum donnae archaic ungulate Arctocyonidae Lancian-Pu1 mixed North America Boyer et al., 2010
UM 1836 ?Protungulatum donnae archaic ungulate Arctocyonidae Lancian-Pu1 mixed North America Szalay and Dagosto, 1980
AMNH 16343 Loxolophus hyattianus archaic ungulate Artocyonidae Puercan North America Matthew, 1937
AMNH 16543 Arctocyon corrugatus (formerly Claenodon corrugatus) archaic ungulate Artocyonidae Torrejonian North America Matthew, 1937
AMNH 16591 Chriacus sp. archaic ungulate Artocyonidae Torrejonian North America Matthew, 1937
MNHN.F.CR17, MNHN.F.CR16 Arctocyon primaevus archaic ungulate Artocyonidae Thanetian Europe Russell, 1964; Argot, 2013
USGS 2353 Chriacus sp. archaic ungulate Artocyonidae Wasatchian North America Rose, 1987; O’Leary and Rose, 1995
AMNH 16500 Ectoconus ditrigonus (formerly E. majusculus) archaic ungulate Periptychidae Puercan North America Matthew, 1937
UNM-B029 Mithrandir gillianus (formerly Gillisonchus gillianus) archaic ungulate Periptychidae Puercan North America Rigby, 1981
AMNH 3636 ?Periptychus carinidens (formerly P. rhabdodon) archaic ungulate Periptychidae Torrejonian North America Matthew, 1937
AMNH 17075 ?Periptychus carinidens (formerly P. rhabdodon) archaic ungulate Periptychidae Torrejonian North America Matthew, 1937
USGS 2352 Diacodexis metsiacus Artiodactyla Diacodexeidae Wasatchian North America Rose, 1982
UALVP 49114 Pronothodectes gaoi “Plesiadapiformes” Plesiadapidae Tiffanian North America Boyer et al., 2010
AMNH 17379 ?NAnnodectes gidleyi (formerly Plesiadapis gidleyi) “Plesiadapiformes” Plesiadapidae Tiffanian North America Simpson, 1935
UM 64588 Plesiadapis rex “Plesiadapiformes” Plesiadapidae Tiffanian North America Boyer et al., 2010
MNHN BR 3L and B4L Plesiadapis tricuspidens “Plesiadapiformes” Plesiadapidae Thanetian Europe Szalay et al., 1975
UM 87990 Plesiadapis cookei “Plesiadapiformes” Plesiadapidae Clarkforkian North America Bloch et al., 2007
UM 108210 and 82606 Ignacius clarkforkensis “Plesiadapiformes” Paramomyidae Clarkforkian North America Bloch et al., 2007
UM 101963 Carpolestes simpsoni “Plesiadapiformes” Carpolestidae Clarkforkian North America Bloch and Boyer,2002
AMNH 2549 Pantolambda bathmodon Pantodonta   Torrejonian North America Matthew, 1937
AMNH 16663 Pantolambda bathmodon Pantodonta   Torrejonian North America Matthew, 1937
AMNH 16410 Onychodectes tisonensis Taeniodonta Conoryctidae Puercan North America Schoch, 1986
TMM 41364-1 Psittacotheriummultifragum Taeniodonta Stylinodontidae Torrejonian North America Schoch, 1986
FMNH P 26090 Ectoganusgliriformis Taeniodonta Stylinodontidae Tiffanian-Clarkforkian North America Schoch, 1986
FMNH P 26083 Ectoganus lobdelli (formerly Lampadophorus expectatus) Taeniodonta Stylinodontidae Tiffanian-Clarkforkian North America Schoch, 1986
YPM 27201 Ectoganus sp. Taeniodonta Stylinodontidae Wasatchian North America Schoch, 1986
YPM 11096 Stylinodon mirus Taeniodonta Stylinodontidae Bridgerian North America Schoch, 1986
AMNH 16610 Deltherium Tillodontia Deltatheriidae Torrejonian North America Matthew, 1937
PU 14389 Theria indet.     Fort Union Formation North America Jenkins, 1973
LSUMG V-802 Theria indet.     Puercan North America Standhardt, 1986

 

APPENDIX 5.

Intraobserver error results. We performed five trials in which we plotted all six landmarks (LMs) on five specimens for each trial. Specimens were chosen to represent the overall variation in the study (i.e., at the maxima and minima of PC1 and PC2, see Appendix 32). We report the variances for each LM placement for each specimen across the five trials, as well as the mean variance across all LMs for a single specimen, and the mean variance across all specimens for a single LM. See Appendix 6 for F test comparison of differences in variance across all LMs. We report the genus and species, sex (in parentheses), and specimen number for each specimen used in this repeatability study. The specimen for Caluromys philander was taken from Argot (2001, figure 8) and lacks sex information; see Methods. Specimen ID Numbers used in this study are the same throughout; see Table 4 for additional specimen information.

  Specimen Number ID Number LM1 LM2 LM3 LM4 LM5 LM6 Mean of Variances Across LMs
Cavia porcellus  (F) UWBM 72830 80 5.453E-04 1.599E-04 1.096E-05 6.610E-05 1.795E-04 4.135E-05 1.672E-04
Caluromys philander (NA) Argot, 2001, fig. 8 3 3.751E-05 4.613E-05 9.017E-05 2.406E-05 2.586E-05 6.837E-05 4.868E-05
Dipodomys deserti (F) UWBM 78740 95 7.200E-05 1.451E-05 3.171E-05 8.272E-05 1.913E-04 6.401E-06 6.643E-05
Lepus americanus (F) UWBM 21111 62 8.579E-06 4.393E-05 2.749E-04 1.938E-05 4.885E-05 5.885E-04 1.640E-04
Mustela erminea (M) UWBM 72863 51 9.250E-05 1.794E-04 3.547E-05 1.169E-05 7.590E-05 6.506E-05 7.668E-05
Mean of Variances Across Specimens   1.512E-04 8.878E-05 8.864E-05 4.079E-05 1.043E-04 1.539E-04  

APPENDIX 6.

Results from F tests of variances pairwise across all landmarks. Specimens are those used in the repeatability study for measurement error (Appendix 5), variances were calculated across Euclidean distances from the centroid for each landmark (LM), and across all five trials for a single specimen. P-values are reported for each pairwise F test, with significance as follows: * for p < 0.05; ** for p < 0.01.

  LM1 LM2 LM3 LM4 LM5 LM6
Cavia porcellus
  LM1 - 0.262 ** 0.065 0.307 *
  LM2 0.262 - * 0.413 0.913 0.219
  LM3 ** * - 0.110 * 0.227
  LM4 0.065 0.413 0.110 - 0.357 0.661
  LM5 0.307 0.913 * 0.357 - 0.184
  LM6 * 0.219 0.227 0.661 0.184 -
Caluromys philander
  LM1 - 0.846 0.416 0.677 0.727 0.575
  LM2 0.846 - 0.532 0.544 0.589 0.712
  LM3 0.416 0.532 - 0.229 0.254 0.795
  LM4 0.677 0.544 0.229 - 0.946 0.336
  LM5 0.727 0.589 0.254 0.946 - 0.369
  LM6 0.575 0.712 0.795 0.336 0.369 -
Dipodomys deserti
  LM1 - 0.150 0.447 0.896 0.367 *
  LM2 0.150 - 0.468 0.120 * 0.447
  LM3 0.447 0.468 - 0.376 0.110 0.150
  LM4 0.896 0.120 0.376 - 0.437 *
  LM5 0.367 * 0.110 0.437 - **
  LM6 * 0.447 0.150 * ** -
Lepus americanus
  LM1 - 0.143 ** 0.449 0.121 **
  LM2 0.143 - 0.103 0.447 0.921 *
  LM3 ** 0.103 - * 0.123 0.479
  LM4 0.449 0.447 * - 0.392 **
  LM5 0.121 0.921 0.123 0.392 - *
  LM6 ** * 0.479 ** * -
Mustela erminea
  LM1 - 0.537 0.376 0.070 0.853 0.741
  LM2 0.537 - 0.145 * 0.425 0.350
  LM3 0.376 0.145 - 0.308 0.479 0.571
  LM4 0.070 * 0.308 - 0.097 0.125
  LM5 0.853 0.425 0.479 0.097 - 0.885
  LM6 0.741 0.350 0.571 0.125 0.885 -

APPENDIX 7.

Means, standard deviations, and percent preservation for multituberculate measurements by morphotype. We include all specimens except for the two specimens tentatively attributed to morphotype MuA (i.e., ?MuA), see text for more details. See Table 1 for measurement descriptions; see Table 2 for data (data excludes minimum values). NA indicates no specimens preserved the measurement (i.e., NA for means) or only one specimen preserved the measurement (i.e., NA for SD). Bold values indicate specimen percent preservation (i.e., the number of specimens that preserve that measurement divided by the total number of specimens in the morphotype) greater than or equal to 80%. We calculate the coefficient of variation (CV) for morphotypes containing more than two specimens. Abbreviations: CV, coefficient of variation; n, number of specimens; SD, standard deviation.

  TDW AW TLW NCW UCW RCW UCL RCL UCD RCD
Full Dataset (n= 28)                    
Mean 6.86 3.55 4.09 2.05 1.68 2.27 2.65 2.48 2.92 2.80
SD 3.86 1.95 2.33 1.02 0.90 1.32 1.46 1.55 1.64 1.44
% Preservation 39.29 57.14 57.14 53.57 89.29 71.43 89.29 78.57 89.29 67.86
MuA (n= 8)                    
Mean 3.884 2.025 2.485 1.185 0.874 1.125 1.363 1.136 1.480 1.494
SD 0.187 0.093 0.140 0.135 0.096 0.083 0.085 0.081 0.121 0.069
% Preservation 62.50 75.00 87.50 62.50 100.00 75.00 100.00 87.50 100.00 62.50
CV 0.048 0.046 0.056 0.114 0.110 0.073 0.063 0.071 0.082 0.046
MuB (n= 1)                    
Mean NA NA NA 1.240 1.080 NA 1.465 NA 1.670 NA
SD NA NA NA NA NA NA NA NA NA NA
% Preservation 0.00 0.00 0.00 100.00 100.00 0.00 100.00 0.00 100.00 0.00
MuC (n= 7)                    
Mean 5.875 2.933 3.726 1.640 1.386 1.634 2.200 1.803 2.409 2.226
SD 0.827 0.232 0.400 0.277 0.254 0.246 0.205 0.129 0.252 0.192
% Preservation 28.57 71.43 71.43 42.86 85.71 85.71 100.00 85.71 100.00 85.71
CV 0.141 0.079 0.107 0.169 0.183 0.151 0.093 0.072 0.105 0.086
MuD (n= 1)                    
Mean NA NA NA NA NA 2.160 NA 2.135 NA 2.350
SD NA NA NA NA NA NA NA NA NA NA
% Preservation 0.00 0.00 0.00 0.00 0.00 100.00 0.00 100.00 0.00 100.00
MuE (n= 5)                    
Mean 8.275 4.213 5.155 2.475 1.933 2.488 3.076 2.375 3.416 3.053
SD 0.205 0.265 0.106 0.108 0.314 0.110 0.393 0.156 0.337 0.337
% Preservation 40.00 40.00 40.00 60.00 100.00 40.00 80.00 40.00 80.00 60.00
CV 0.025 0.063 0.021 0.044 0.162 0.044 0.128 0.066 0.099 0.110
MuF (n= 6)                    
Mean 13.865 7.192 9.548 3.740 3.174 4.334 5.221 4.826 5.777 5.220
SD 0.226 0.467 0.626 0.420 0.526 0.461 0.282 0.639 0.660 0.928
% Preservation 33.33 50.00 33.33 50.00 83.33 83.33 83.33 100.00 83.33 66.67
CV 0.016 0.065 0.066 0.112 0.166 0.106 0.054 0.133 0.114 0.178

APPENDIX 8.

Means, standard deviations, and percent preservation for therian measurements by morphotype. We include all specimens except for the specimen in morphotype MeA, which lacked any measureable features. See Table 1 for measurement descriptions; see Table 3 for data (data excludes minimum values). NA indicates no specimens preserved the measurement (i.e., NA for means) or only one specimen preserved the measurement (i.e., NA for SD). Bold values indicate specimen percent preservation (i.e., the number of specimens that preserve that measurement divided by the total number of specimens in the morphotype) greater than or equal to 80%. We calculate the coefficient of variation (CV) for morphotypes containing more than two specimens (i.e., only EuD). Abbreviations: CV, coefficient of variation; n, number of specimens; SD, standard deviation.

  TDW AW TLW NCW TW CW TL CL TD CD
Full Dataset (n = 14)                    
Mean 9.560 7.189 7.414 4.713 2.438 4.836 3.084 3.026 2.708 4.416
SD 0.357 3.926 3.888 2.812 1.351 2.838 2.084 1.824 1.360 2.836
% Preservation 21.43 78.57 78.57 42.86 92.86 78.57 92.86 78.57 71.43 57.14
EuA (n = 1)                    
Mean NA 3.850 3.850 NA 1.330 2.406 1.630 1.579 1.756 1.920
SD NA NA NA NA NA NA NA NA NA NA
% Preservation 0.00 100.00 100.00 0.00 100.00 100.00 100.00 100.00 100.00 100.00
EuB (n = 1)                    
Mean NA 4.765 5.120 NA 1.705 2.895 1.960 1.945 2.355 NA
SD NA NA NA NA NA NA NA NA NA NA
% Preservation 0.00 100.00 100.00 0.00 100.00 100.00 100.00 100.00 100.00 0.00
EuC (n = 2)                    
Mean 9.520 5.635 5.735 3.918 1.670 3.945 2.680 2.515 3.095 3.310
SD NA NA NA 0.138 NA NA NA NA 0.092 NA
% Preservation 50.00 50.00 50.00 100.00 50.00 50.00 50.00 50.00 100.00 50.00
EuD (n = 5)                    
Mean 9.580 5.463 5.780 3.880 1.923 3.510 1.840 2.056 2.279 2.528
SD 0.502 0.223 0.310 0.467 0.168 0.245 0.221 0.221 0.129 0.168
% Preservation 40.00 100.00 100.00 40.00 100.00 100.00 100.00 100.00 80.00 60.00
CV 0.052 0.041 0.054 0.120 0.087 0.070 0.120 0.108 0.057 0.066
EuE (n = 2)                    
Mean NA 10.118 10.275 NA 2.795 7.290 4.453 4.845 6.280 6.423
SD NA 0.803 0.813 NA 0.219 0.467 0.173 0.375 NA 1.559
% Preservation 0.00 100.00 100.00 0.00 100.00 100.00 100.00 100.00 50.00 100.00
EuF (n = 1)                    
Mean NA 17.280 17.395 NA 5.480 11.820 6.945 7.280 NA 9.670
SD NA NA NA NA NA NA NA NA NA NA
% Preservation 0.00 100.00 100.00 0.00 100.00 100.00 100.00 100.00 0.00 100.00
EuG (n = 1)                    
Mean NA NA NA 10.300 5.095 NA 7.435 NA NA NA
SD NA NA NA NA NA NA NA NA NA NA
% Preservation 0.00 0.00 0.00 100.00 100.00 0.00 100.00 0.00 0.00 0.00
ThA (n = 1)                    
Mean NA NA NA 2.380 1.210 NA 1.340 NA 1.380 NA
SD NA NA NA NA NA NA NA NA NA NA
% Preservation 0.00 0.00 0.00 100.00 100.00 0.00 100.00 0.00 100.00 0.00

 

APPENDIX 9.

The results of One-Way ANOVAs of difference for all multituberculate measurements across all morphotypes. Asterisks (****) indicate significant p-values (< 0.0001). Both biozone (b) and residuals (r) values are given for Sum of Squares, df, and Mean Squares. See Table 1 for measurement details; see Table 3 for data.

  TDW AW TLW NCW UCW RCW UCL RCL UCD RCD
  b r b r b r b r b r b r b r b r b r b r
Sum of Squares 148.368 0.918 56.520 0.764 80.532 1.160 14.012 0.603 17.551 1.889 31.699 1.198 49.847 1.083 48.562 2.192 61.774 2.568 34.327 3.012
df 3 7 3 12 3 12 4 10 4 20 4 15 4 20 4 17 4 20 4 14
Mean Squares 49.456 0.131 18.840 0.064 26.844 0.097 3.503 0.060 4.388 0.094 7.925 0.080 12.462 0.054 12.141 0.129 15.444 0.128 8.582 0.215
F 377.07 295.97 277.59 58.10 46.45 99.19 230.16 94.17 120.27 39.89
p-value **** **** **** **** **** **** **** **** **** ****

APPENDIX 10.

Probabilities from Tukey honest significant difference (HSD) post hoc test of multituberculate measurements by morphotype. All measurements had significant ANOVA results, and therefore all measurements were subjected to the Tukey HSD test and have results below. Significance indicated by the following: * for p < 0.05; ** for p < 0.01; *** for p < 0.001; **** for p < 0.0001. NA indicates the morphotype did not include that particular measurement and therefore could not be subjected to ANOVA or Tukey tests.

Measurement   MuA MuB MuC MuD MuE MuF
TDW MuA - NA ** NA **** ****
  MuB NA - NA NA NA NA
  MuC ** NA - NA ** ****
  MuD NA NA NA - NA NA
  MuE **** NA ** NA - ****
  MuF **** NA **** NA **** -
AW MuA - NA *** NA **** ****
  MuB NA - NA NA NA NA
  MuC *** NA - NA *** ****
  MuD NA NA NA - NA NA
  MuE **** NA *** NA - ****
  MuF **** NA **** NA **** -
TLW MuA - NA *** NA **** ****
  MuB NA - NA NA NA NA
  MuC *** NA - NA *** ****
  MuD NA NA NA - NA NA
  MuE **** NA *** NA - ****
  MuF **** NA **** NA **** -
NCW MuA - 1.000 0.158 NA *** ****
  MuB 1.000 - 0.635 NA ** ****
  MuC 0.158 0.635 - NA * ****
  MuD NA NA NA - NA NA
  MuE *** ** * NA - ***
  MuF **** **** **** NA *** -
UCW MuA - 0.968 * NA *** ****
  MuB 0.968 - 0.885 NA 0.123 ****
  MuC * 0.885 - NA 0.056 ****
  MuD NA NA NA - NA NA
  MuE *** 0.123 0.056 NA - ****
  MuF **** **** **** NA **** -
RCW MuA - NA * * *** ****
  MuB NA - NA NA NA NA
  MuC * NA - 0.451 * ****
  MuD * NA 0.451 - 0.874 ****
  MuE *** NA * 0.874 - ****
  MuF **** NA **** **** **** -
UCL MuA - 0.993 **** NA **** ****
  MuB 0.993 - 0.054 NA **** ****
  MuC **** 0.054 - NA *** ****
  MuD NA NA NA - NA NA
  MuE **** **** *** NA - ****
  MuF **** **** **** NA **** -
RCL MuA - NA * 0.114 ** ****
  MuB NA - NA NA NA NA
  MuC * NA - 0.908 0.329 ****
  MuD 0.114 NA 0.908 - 0.981 ****
  MuE ** NA 0.329 0.981 - ****
  MuF **** NA **** **** **** -
UCD MuA - 0.986 *** NA **** ****
  MuB 0.986 - 0.335 NA ** ****
  MuC *** 0.335 - NA ** ****
  MuD NA NA NA - NA NA
  MuE **** ** ** NA - ****
  MuF **** **** **** NA **** -
RCD MuA - NA 0.123 0.473 ** ****
  MuB NA - NA NA NA NA
  MuC 0.123 NA - 0.999 0.141 ****
  MuD 0.473 NA 0.999 - 0.688 ***
  MuE ** NA 0.141 0.688 - ***
  MuF **** NA **** *** *** -

APPENDIX 11.

Boxplots for all multituberculate measurement with significant ANOVA results according to morphotype. Boxplots include minimum, quartiles, median, and maximum values. See Table 1 for measurements, Table 2 for data, and Appendix 9-Appendix 10 for ANOVA and Tukey HSD results, respectively. Specimens tentatively attributed to morphotype MuA (i.e., ?MuA), were not included in ANOVA and Tukey tests.

appendix 11 

 

APPENDIX 12.

Variances for all multituberculate measurement with significant ANOVA results according to morphotype. See Appendix 2 for means, maxima, minima, and quartiles. See Table 1 for measurements, Table 2 for data, and Appendix 9-Appendix 10 for ANOVA and Tukey HSD results, respectively.

 

 

APPENDIX 13.

Principal Components 1 and 2 on the full set of variables (i.e., measurements; excluding TDW, AW, and TLW; n = 10 specimens). All measurements are standardized to (i.e., “relative to”) RCW. The first and second principal components explain 64% and 20% of the variation, respectively. See Appendix 14 for all principal component loadings and variances. Plotted multituberculate morphotypes include: MuA (blue), MuC (red), MuE (orange), and MuF (green). See Table 1 for measurements and Table 2 for data.

appendix 13

 

 

APPENDIX 14.

Measurement loading and variance results of Principal Components Analysis on linear measurements of multituberculate specimens from our assemblage (n = 10). Measurements include NCW, RCL, RCD, UCL, UCD, and UCW, all standardized to RCW (Table 1; Appendix 13). Loadings in bold represent dominant loadings for each principal component (i.e., values greater than (1/(number of columns)2).

  PC1 PC2 PC3 PC4 PC5 PC6
Loadings  
relUCD 0.490 0.069 0.120 0.354 -0.130 0.774
relRCL 0.470 -0.196 -0.096 -0.236 0.822 -0.019
relRCD 0.441 0.311 -0.206 0.597 -0.044 -0.556
relUCL 0.438 -0.083 -0.537 -0.527 -0.485 -0.027
relNCW 0.121 0.839 0.329 -0.413 0.050 -0.004
relUCW 0.372 -0.387 0.733 -0.122 -0.261 -0.303
Variance  
Percent Variance 0.637 0.199 0.085 0.048 0.022 0.009
Cumulative Variance 0.637 0.836 0.921 0.969 0.991 1.000

 

APPENDIX 15.

Principal Components 1 and 2 on measurements NCW, RCL, UCL, and UCW, and standardized to (i.e., “relative to”) RCW. The first and second principal components explain 61% and 23% of the variation, respectively. See Appendix 16 for all principal component loadings and variances. Plotted multituberculate morphotypes include: MuA (blue), MuC (red), MuE (orange), and MuF (green). This dataset is similar to that of Appendix 13, but excludes measurement RCD and includes one additional specimen (n = 11). See Table 1 for measurements and Table 2 for data.

appendix 15

 

APPENDIX 16.

Measurement loading and variance results of Principal Components Analysis on linear measurements of multituberculate specimens from our assemblage (n = 11). Measurements include NCW, RCD, UCL, UCD, and UCW, all standardized to RCW (Table 1; Appendix 15). Loadings in bold represent dominant loadings for each principal component.

  PC1 PC2 PC3 PC4 PC5
Loadings          
relUCD 0.556 0.022 0.092 -0.309 -0.766
relRCD 0.519 -0.232 -0.201 -0.557 0.571
relUCL 0.474 0.183 -0.602 0.615 0.030
relNCW 0.223 -0.798 0.366 0.423 0.012
relUCW 0.382 0.524 0.674 0.196 0.294
Variance          
Percent Variance 0.608 0.231 0.099 0.052 0.010
Cumulative Variance 0.608 0.839 0.938 0.990 1.000

 

APPENDIX 17.

Principal Components 1 and 2 on measurements NCW, RCL, UCL, and UCW, and standardized to (“relative to”) RCW, see Table 1 for measurements. The first and second principal components explain 44% and 24% of the variation, respectively. See Appendix 18 for all principal component loadings and variances. Plotted multituberculate morphotypes include: MuA (blue), MuC (red), MuE (orange), and MuF (green; Table 2); published specimens include: ?Cimexomys minor, UMVP 1404 (Deischl 1964); Microcosmodon conus, UALVP 42816 (Fox 2005); Mesodma formosa, UMVP 1405 (Deischl 1964); M. thompsoni (A), UMVP 1406 (Deischl 1964); M. thompsoni (B), UMVP 1403 (Deischl 1964); Multituberculata, AMNH 118267 (Kielan-Jaworowska and Gambaryan 1994); Stygimys kuszmauli (C), UA 11994 (Krause and Jenkins 1983); and S. kuszmauli (D), UMVP 1407 (Deischl 1964; Krause and Jenkins 1983); see Appendix 3 for additional details on published material.

appendix 17 

 

APPENDIX 18.

Measurement loading and variance results of Principal Components Analysis on linear measurements of multituberculate specimens. Measurements include NCW, RCL, UCL, and UCW, all standardized to RCW (Table 1; Appendix 17). Specimens include nine specimens from our assemblage and seven specimens from the published literature (see Appendix 17 for more details). Loadings in bold represent dominant loadings for each principal component.

  PC1 PC2 PC3 PC4
Loadings        
relRCL 0.652 -0.191 -0.100 -0.727
relUCL 0.610 -0.379 -0.182 0.672
relNCW 0.285 0.843 -0.446 0.095
relUCW 0.348 0.331 0.871 0.106
Variance        
Percent Variance 0.435 0.238 0.224 0.103
Cumulative Variance 0.435 0.673 0.897 1.000

 

APPENDIX 19.

The results of One-Way ANOVAs of difference for all therians measurements across all morphotypes. Significance indicated by the following: * for p < 0.05; ** for p < 0.01; *** for p < 0.001; **** for p < 0.0001. Both biozone (b) and residuals (r) values are given for Sum of Squares, df, and Mean Squares. See Table 1 for measurement details; see Table 3 for data.

  TDW AW TLW NCW UCW RCW UCL RCL UCD RCD
  b r b r b r b r b r b r b r b r b r b r
Sum of Squares 0.002 0.252 153.315 0.844 150.124 1.047 39.311 0.237 21.757 0.161 80.078 0.459 51.904 0.225 32.942 0.336 16.590 0.059 53.800 2.487
df 1 1 5 5 5 5 3 2 7 5 5 5 7 5 5 5 5 4 4 3
Mean Squares 0.002 0.252 30.663 0.169 30.025 0.209 13.104 0.118 3.108 0.032 16.016 0.092 7.415 0.045 6.588 0.067 3.318 0.015 13.450 0.829
F 0.010 181.730 143.440 110.667 96.810 174.614 164.692 98.036 226.415 16.223
p-value 0.938 **** **** ** **** **** **** **** **** *

APPENDIX 20.

Probabilities from Tukey honest significant difference (HSD) post hoc test of therian measurements by morphotype. Measurements subjected to the Tukey HSD test are those with significant ANOVA results (i.e., all measurements except TDW); see Table 1 for measurements and Table 3 for data. Significance indicated by the following: * for p < 0.05; ** for p < 0.01; *** for p < 0.001; **** for p < 0.0001. NA indicates the morphotype did not include that particular measurement and therefore could not be subjected to ANOVA or Tukey tests.

    EuA EuB EuC EuD EuE EuF EuG ThA
AW EuA - 0.643 0.155 0.094 *** **** NA NA
  EuB 0.643 - 0.681 0.655 *** **** NA NA
  EuC 0.155 0.681 - 0.998 ** **** NA NA
  EuD 0.094 0.655 0.998 - *** **** NA NA
  EuE *** *** ** *** - *** NA NA
  EuF **** **** **** **** *** - NA NA
  EuG NA NA NA NA NA NA - NA
  ThA NA NA NA NA NA NA NA -
                   
TLW EuA - 0.463 0.182 0.073 *** **** NA NA
  EuB 0.463 - 0.916 0.769 ** **** NA NA
  EuC 0.182 0.916 - 1.000 ** *** NA NA
  EuD 0.073 0.769 1.000 - *** **** NA NA
  EuE *** ** ** *** - *** NA NA
  EuF **** **** *** **** *** - NA NA
  EuG NA NA NA NA NA NA - NA
  ThA NA NA NA NA NA NA NA -
                   
NCW EuA - NA NA NA NA NA NA NA
  EuB NA - NA NA NA NA NA NA
  EuC NA NA - 0.999 NA NA * 0.162
  EuD NA NA 0.999 - NA NA * 0.169
  EuE NA NA NA NA - NA NA NA
  EuF NA NA NA NA NA - NA NA
  EuG NA NA * * NA NA - **
  ThA NA NA 0.162 0.169 NA NA ** -
                   
TW EuA - 0.794 0.852 0.219 * *** *** 0.999
  EuB 0.794 - 1.000 0.929 * *** *** 0.574
  EuC 0.852 1.000 - 0.872 * *** *** 0.638
  EuD 0.219 0.929 0.872 - * *** *** 0.126
  EuE * * * * - *** ** **
  EuF *** *** *** *** *** - 0.776 ***
  EuG *** *** *** *** ** 0.776 - ***
  ThA 0.999 0.574 0.638 0.123 ** *** *** -
                   
CW EuA - 0.847 0.093 0.121 *** **** NA NA
  EuB 0.847 - 0.289 0.511 *** **** NA NA
  EuC 0.093 0.289 - 0.771 ** *** NA NA
  EuD 0.121 0.511 0.771 - *** **** NA NA
  EuE *** *** ** *** - *** NA NA
  EuF **** **** *** **** *** - NA NA
  EuG NA NA NA NA NA NA - NA
  ThA NA NA NA NA NA NA NA -
                   
TL EuA - 0.932 0.139 0.972 ** *** *** 0.962
  EuB 0.932 - 0.391 0.999 ** *** *** 0.524
  EuC 0.139 0.391 - 0.125 * *** *** 0.059
  EuD 0.972 0.999 0.125 - *** **** **** 0.487
  EuE ** ** * *** - ** *** ***
  EuF *** *** *** **** ** - 0.724 ***
  EuG *** *** *** **** *** 0.724 - ****
  ThA 0.962 0.524 0.059 0.487 *** *** **** -
                   
CL EuA - 0.901 0.261 0.592 ** *** NA NA
  EuB 0.901 - 0.653 0.998 ** *** NA NA
  EuC 0.261 0.653 - 0.623 ** *** NA NA
  EuD 0.592 0.998 0.623 - *** *** NA NA
  EuE ** ** ** *** - ** NA NA
  EuF *** *** *** *** ** - NA NA
  EuG NA NA NA NA NA NA - NA
  ThA NA NA NA NA NA NA NA -
                   
TD EuA - 0.128 ** 0.096 *** NA NA 0.393
  EuB 0.128 - * 0.989 *** NA NA *
  EuC ** * - ** *** NA NA **
  EuD 0.096 0.989 ** - *** NA NA *
  EuE *** *** *** *** - NA NA ***
  EuF NA NA NA NA NA - NA NA
  EuG NA NA NA NA NA NA - NA
  ThA 0.393 * ** * *** NA NA -
                   
CD EuA - NA 0.810 0.970 0.101 * NA NA
  EuB NA - NA NA NA NA NA NA
  EuC 0.810 NA - 0.932 0.235 0.060 NA NA
  EuD 0.970 NA 0.932 - 0.069 * NA NA
  EuE 0.101 NA 0.235 0.069 - 0.215 NA NA
  EuF * NA 0.060 * 0.215 - NA NA
  EuG NA NA NA NA NA NA - NA

APPENDIX 21.

Boxplots for all therian measurement with significant ANOVA results according to morphotype (i.e., all measurement except TDW). Boxplots include minimum, quartiles, median, and maximum values. See Table 1 for measurements, Table 3 for data, and Appendix 19-Appendix 20 for ANOVA and Tukey HSD results, respectively. The specimen attributed to morphotype MeA was not included in ANOVA and Tukey tests because it lacked any morphologies preserving our measurements.

appendix 21

 

 

APPENDIX 22.

Variances for therian measurements with significant ANOVA results according to morphotype (i.e., all measurements except TDW) and preserving at least two specimens (i.e., only EuC, EuD, and EuE; see Appendix 8). See Appendix 21 for means, maxima, minima, and quartiles. See Table 1 for measurements, Table 3 for data, and Appendix 19-Appendix 20 for ANOVA and Tukey HSD results, respectively.

 

appendix 22

 

APPENDIX 23.

Means and standard deviations for multituberculate measurements for entire dataset and by biozone. For measurement descriptions see Table 1; for data see Table 2. NA indicates no specimens preserved the measurement (i.e., NA for mean) or only one specimen preserved the measurement (i.e., NA for SD). Bold values indicate specimen percent preservation (i.e., the number of specimens that preserve that measurement divided by the total number of specimens) greater than or equal to 80%. Abbreviations: BCA, Bug Creek Anthills specimens of mixed age (see text for details); n, number of specimens; Pu1, early Puercan 1 biozone; Pu3, late Puercan biozone; SD, standard deviation.

  TDW AW TLW NCW UCW RCW UCL RCL UCD RCD
Full Dataset (n = 30)
Mean 6.859 3.551 4.089 2.049 1.639 2.219 2.576 2.482 2.826 2.801
SD 3.864 1.954 2.334 1.022 0.903 1.302 1.472 1.555 1.607 1.440
% Preservation 36.67 53.33 53.33 50.00 86.67 70.00 86.67 73.33 90.00 63.33
Lancian (n = 11)
Mean 10.475 5.232 6.199 3.066 2.243 3.151 3.627 3.587 4.145 3.650
SD 5.874 2.709 3.891 1.390 1.194 1.474 1.950 1.687 2.018 1.806
% Preservation 27.27 45.45 36.36 36.36 81.82 81.82 81.82 90.91 81.82 72.73
BCA (n = 12)
Mean 5.366 2.686 3.194 1.723 1.220 1.530 1.844 1.438 2.009 2.135
SD 2.054 1.006 1.177 0.637 0.485 0.621 0.732 0.586 0.828 0.800
% Preservation 58.33 66.67 75.00 66.67 100.00 66.67 91.67 66.67 91.67 66.67
Pu1 (n = 4)
Mean 6.460 3.090 4.250 1.960 1.965 1.470 2.653 1.858 2.595 2.335
SD NA NA NA NA 0.559 0.325 0.764 0.039 0.970 NA
% Preservation 25.00 25.00 25.00 25.00 50.00 50.00 75.00 50.00 100.00 25.00
Pu3 (n = 3)  
Mean NA 3.038 3.818 1.360 1.285 1.530 2.033 1.760 2.177 2.300
SD NA 0.004 0.004 0.170 0.213 0.156 0.511 0.007 0.447 0.007
% Preservation 0.00 66.67 66.67 66.67 100.00 66.67 100.00 66.67 100.00 66.67

APPENDIX 24.

Means and standard deviations for therian measurements by biozone. We include all specimens except for the specimen in morphotype MeA, which lacked any measureable features. For measurement descriptions see Table 1; for data see Table 3 (data excludes minimum values). NA indicates no specimens preserved the measurement (i.e., NA for means) or only one specimen preserved the measurement (i.e., NA for SD). Bold values indicate specimen percent preservation (i.e., the number of specimens that preserve that measurement divided by the total number of specimens) greater than or equal to 80%. Abbreviations: BCA, Bug Creek Anthills specimens of mixed age (see text for details); n, number of specimens; Pu1, early Puercan 1 biozone; Pu3, late Puercan biozone; SD, standard deviation.

  TDW AW TLW NCW TW CW TL CL TD CD
Full Dataset (n = 14)
Mean 9.560 7.189 7.414 4.713 2.438 4.836 3.084 3.026 2.708 4.416
SD 0.357 3.926 3.888 2.812 1.351 2.838 2.084 1.824 1.360 2.836
% Preservation 21.43 78.57 78.57 42.86 92.86 78.57 92.86 78.57 71.43 57.14
Lancian (n = 2)
Mean NA 4.765 5.120 2.380 1.458 2.895 1.650 1.945 1.868 NA
SD NA NA NA NA 0.350 NA 0.438 NA 0.689 NA
% Preservation 0.00 50.00 50.00 50.00 100.00 50.00 100.00 50.00 100.00 0.00
BCA (n = 6)
Mean 9.560 5.492 5.773 3.860 1.881 3.583 1.980 2.133 2.429 2.724
SD 0.357 0.212 0.278 0.332 0.182 0.282 0.396 0.272 0.354 0.414
% Preservation 50.00 100.00 100.00 50.00 100.00 100.00 100.00 100.00 83.33 66.67
Pu1 (n = 2)
Mean NA 10.685 10.850 4.015 2.950 7.620 4.575 5.110 4.720 7.525
SD NA NA NA NA NA NA NA NA 2.206 NA
% Preservation 0.00 50.00 50.00 50.00 50.00 50.00 50.00 50.00 100.00 50.00
Pu3 (n = 4)
Mean NA 10.227 10.315 10.300 3.636 7.062 5.085 4.480 1.756 5.637
SD NA 6.741 6.793 NA 1.987 4.708 2.676 2.852 NA 3.885
% Preservation 0.00 75.00 75.00 25.00 100.00 75.00 100.00 75.00 25.00 75.00

APPENDIX 25.

The results of One-Way ANOVAs of difference for all multituberculate measurements across all biozones. Asterisk indicates significant p-values (< 0.05). Both biozone (b) and residuals (r) values are given for Sum of Squares, df, and Mean Squares. See Table 1 for measurement details; see Table 2 for data and Appendix 26 for Tukey HSD results.

  TDW AW TLW NCW UCW RCW UCL RCL UCD RCD
  b r b r b r b r b r b r b r b r b r b r
Sum of Squares 54.980 94.306 20.851 36.433 25.180 56.513 5.946 8.669 5.972 14.405 13.689 20.215 16.729 37.464 22.739 28.015 24.477 42.655 10.034 27.305
df 2 8 3 12 3 12 3 11 3 22 3 17 3 22 3 18 3 23 3 15
Mean Squares 27.490 11.788 6.950 3.036 8.393 4.709 1.982 0.788 1.991 0.655 4.563 1.189 5.576 1.703 7.580 1.556 8.159 1.855 3.345 1.820
F 2.332 2.289 1.782 2.515 3.040 3.837 3.275 4.870 4.399 1.837
p-value 0.159 0.130 0.130 0.112 0.050 * * * * 0.184

APPENDIX 26.

Probabilities from Tukey honest significant difference (HSD) post hoc test of multituberculate measurements by biozones. Measurements subjected to the Tukey HSD test are those with significant ANOVA results: radial condyle width (RCW), ulnar condyle length (UCL), radial condyle length (RCL), and ulnar condyle depth (UCD). Significance indicated by the following: * for p < 0.05; ** for p < 0.01.

Measurement   Lancian BCA Pu1 Pu3
RCW Lancian - * 0.237 0.264
  BCA * - 1.000 1.000
  Pu1 0.237 1.000 - 1.000
  Pu3 0.264 1.000 1.000 -
 
UCL Lancian - * 0.682 0.286
  BCA * - 0.777 0.996
  Pu1 0.682 0.777 - 0.936
  Pu3 0.286 0.996 0.936 -
 
RCL Lancian - ** 0.310 0.267
  BCA ** - 0.973 0.988
  Pu1 0.310 0.973 - 1.000
  Pu3 0.267 0.988 1.000 -
 
UCD Lancian - * 0.258 0.162
  BCA * - 0.881 0.998
  Pu1 0.258 0.881 - 0.977
  Pu3 0.162 0.998 0.977 -

APPENDIX 27.

Boxplots (above) and variances (below) for each multituberculate measurement with significant ANOVA results according to biozone. Boxplots include minimum, quartiles, median, and maximum values. See Table 1 for measurements, Table 2 for data, Appendix 7 for means, and Appendix 25-Appendix 26 for ANOVA and Tukey HSD results, respectively. Asterisks indicate pairs of significantly different values in Tukey tests (i.e., Lancian specimens are significantly larger than BCA specimens for all measurements).

 

appendix 27

 

APPENDIX 28.

The results of One-Way ANOVAs of difference for all therians measurements across all biozones (for all measurements with specimens in at least three biozones, i.e., excluding TDW). Significance is as follows: * for p < 0.05; ** for p < 0.01. Both biozone (b) and residuals (r) values are given for Sum of Squares, df, and Mean Squares. See Table 1 for measurement details and Table 3 for data.

  AW TLW NCW TW CW TL CL TD CD
  b r b r b r b r b r b r b r b r b r
Sum of Squares 63.066 91.093 58.483 92.688 39.327 0.220 9.791 12.127 35.811 44.726 29.665 22.464 16.641 16.637 10.805 5.844 25.591 30.696
df 3 7 3 7 3 2 3 9 3 7 3 9 3 7 3 6 2 5
Mean
Squares
21.022 13.013 19.494 13.241 13.109 0.110 3.264 1.347 11.937 6.389 9.888 2.496 5.547 2.377 3.602 0.974 12.795 6.139
F 1.615 1.472 119.066 2.422 1.868 3.962 2.334 3.698 2.084
p-value 0.270 0.302 ** 0.133 0.223 * 0.160 0.081 0.220

APPENDIX 29.

Probabilities from Tukey honest significant difference (HSD) post hoc test of therian measurements by biozones. Measurements subjected to the Tukey HSD test are those with significant ANOVA results, only entepicondyle condyle width (NCW) and trochlea depth (TL). Significance is as follows: * for p < 0.05; ** for p < 0.01.

Measurement   Lancian BCA Pu1 Pu3
NCW Lancian - 0.147 0.176 **
  BCA 0.147 - 0.973 **
  Pu1 0.176 0.973 - *
  Pu3 ** ** * -
 
TL Lancian - 0.994 0.470 0.125
  BCA 0.994 - 0.465 0.056
  Pu1 0.470 0.465 - 0.991
  Pu3 0.125 0.056 0.991 -

APPENDIX 30.

Boxplot (left) and variance (right) for eutherian NCW measurement, which had significant ANOVA results according to biozone. Boxplot includes minimum, quartiles, median, and maximum values; variance shown for biozones with n > 1. See Table 1 for measurements, Table 3 for data, Appendix 8 for means, and Appendix 28-Appendix 29 for ANOVA and Tukey HSD results, respectively. Asterisks indicate pairs of significantly different values in Tukey tests (i.e., Pu3 specimens are significantly larger than Lancian and BCA specimens).

appendix 30

 

APPENDIX 31.

Eigenvalues, proportion of variance, and cumulative variance explained from PCAs. We conducted PCAs on two separate datasets: one “full dataset” that included all modern taxa (Table 4), and one “reduced dataset” of eutherians that excluded carnivorans and lagomorphs (see text for more details). Of the 40 total principal components in each PCA, we report only PCs that explained at least 1% of the variance.

  Eigenvalues Proportion of
Variance
Cumulative
Variance
Full Dataset
  PC1 0.0067938 46% 46%
  PC2 0.0018609 13% 59%
  PC3 0.0016220 11% 70%
  PC4 0.0011623 8% 78%
  PC5 0.0007075 5% 83%
  PC6 0.0004502 3% 86%
  PC7 0.0003615 2% 88%
  PC8 0.0003264 2% 91%
  PC9 0.0003162 2% 93%
  PC10 0.0002115 1% 94%
  PC11 0.0001540 1% 95%
Reduced Dataset
  PC1 0.0042641 37% 37%
  PC2 0.0021872 19% 56%
  PC3 0.0015529 13% 69%
  PC4 0.0007259 6% 75%
  PC5 0.0007226 6% 82%
  PC6 0.0004394 4% 85%
  PC7 0.0003591 3% 89%
  PC8 0.0003120 3% 91%
  PC9 0.0002451 2% 93%
  PC10 0.0001782 2% 95%
  PC11 0.0001404 1% 96%

APPENDIX 32.

Principal Component Analysis (PCA) of all modern taxa with specimens labeled. PC1 and PC2 explain 46% and 13% of the total variance, respectively (Appendix 31). Partial warp shapes indicate the minimum and maximum of PC1 on a right humerus in distal view. Black circles are metatherians, gray circles are eutherians. See Table 4 for specimen information. We note the orientation of the maximum and minimum of PC1 is reversed here compared to Figure 3, Figure 20-Figure 21); this is a function of the arbitrary assignment of maximum and minimum in PC space, and it does not affect the shape interpretation.

appendix 32

 

 

 

APPENDIX 33.

Principal Component Analysis (PCA) of all modern taxa with specimens labeled. PC2 and PC3 explain 13% and 11% of the total variance, respectively (Appendix 31). Partial warp shapes indicate the minimum and maximum of PC2. Black circles are metatherians, gray circles are eutherians. See Table 4 for specimen information.

appendix 33

APPENDIX 34.

LDA results for the reduced dataset of extant mammals with known locomotion. LDA analyses used all significant principal components (i.e., those which represented at least 1% of the variation).

Locomotor Group Means
  A F G S Sa Sc Sf T
PC1 0.01276 -0.00884 0.06054 0.05556 -0.01318 -0.03556 -0.01427 0.02452
PC2 0.02255 -0.02874 0.03102 -0.01765 -0.07145 0.05872 0.00177 0.01686
PC3 0.01071 -0.00397 -0.00655 -0.00441 0.00296 0.04311 -0.01621 0.00011
PC4 -0.00049 -0.01497 0.00582 0.00888 0.01229 0.00693 0.00257 0.02051
PC5 0.00474 -0.00238 -0.03417 0.00849 -0.00719 -0.00493 0.00250 0.00677
PC6 0.01928 -0.00531 0.00733 -0.02232 -0.00779 -0.01032 -0.00525 -0.01245
PC7 -0.00652 -0.00415 0.01422 -0.00893 0.01796 0.02135 -0.01010 0.01034
PC8 -0.00155 0.00139 0.01861 0.00473 0.00458 -0.00357 0.00581 -0.00768
PC9 0.00265 0.00418 0.00749 -0.00980 0.00657 -0.01905 -0.00713 0.00275
PC10 0.00117 -0.00358 -0.00796 0.00495 0.00051 -0.00717 0.00358 -0.00140
PC11 0.00427 0.00338 0.00415 0.00051 -0.00679 0.00198 -0.00687 -0.00108

Coefficients of Linear Discriminants
  LD1 LD2 LD3 LD4 LD5 LD6
PC1 2.94717 2.27578 2.17796 9.41316 -6.31096 -4.86250
PC2 26.91399 13.17848 -4.77661 4.56211 2.92216 0.42556
PC3 7.31164 6.68984 1.18431 -11.66506 2.81487 -1.24342
PC4 -5.70621 22.80368 -3.22197 4.88143 -18.81627 11.10793
PC5 2.06893 -3.58513 -21.96368 -10.27321 -13.82449 -4.63802
PC6 48.82373 -21.34994 19.54012 -11.13995 -10.35859 23.00979
PC7 -20.15756 43.27913 29.14487 -15.39684 0.14397 3.82854
PC8 -6.88752 -9.20087 17.93410 29.18532 19.67257 17.61627
PC9 -3.79714 -16.85835 37.88225 -4.34904 -33.12376 -12.11852
PC10 -4.01667 -13.76100 -24.49836 5.73548 -20.80180 21.90751
PC11 44.60443 -8.70142 17.22111 -4.55220 6.04990 -51.18676
Proportions
of Trace
50.42% 21.25% 13.29% 5.64% 4.95% 3.18%

APPENDIX 35.

LDA predictions for locomotor mode for modern specimens in this study. LDA correctly predicts locomotor mode of modern specimens with an accuracy of 74.19%. Published locomotor mode (LM) is indicated, as well as predicted locomotor mode; asterisks indicate specimens whose locomotor mode was incorrectly predicted. See Table 4 for additional specimen information.

Specimen Genus species Family Order Code LM LM Prediction
S2008 Potamogale velox Potamogalidae Afrosoricida 21 Sa T*
39039 Dendrohyrax arboreus Procaviidae Afrosoricida 22 A A
39038 Dendrohyrax arboreus Procaviidae Afrosoricida 23 A Sf*
S2008 Limnogale mergulus Tenrecidae Afrosoricida 24 Sa F*
34168 Echinops telfairi Tenrecidae Afrosoricida 25 Sc Sc
S2008 Echinops telfairi Tenrecidae Afrosoricida 26 Sc T*
S2008 Hemicentetes semispinosus Tenrecidae Afrosoricida 27 Sf T*
S2008 Oryzorictes sp. Tenrecidae Afrosoricida 28 Sf Sf
S2008 Setifer setosus Tenrecidae Afrosoricida 29 T T
S2008 Tenrec ecaudatus Tenrecidae Afrosoricida 30 T T
S2008 Microgale cowani Tenrecidae Afrosoricida 31 T T
S2008 Microgale dobsoni Tenrecidae Afrosoricida 32 T T
S2008 Microgale talazaci Tenrecidae Afrosoricida 33 T Sc*
34167 Cabassous centralis Dasypodidae Cingulata 55 F Sa*
20735 Dasypus novemcinctus Dasypodidae Cingulata 56 F F
22458 Dasypus novemcinctus Dasypodidae Cingulata 57 F F
35468 Euphractus sexcinctus Dasypodidae Cingulata 58 F F
S2008 Echinosorex gymnurus Erinaceidae Erinaceomorpha 59 T T
S2008 Solenodon paradoxus Solenodontidae Soricomorpha 60 Sf Sf
S2008 Petrodromus tetradactylus Macroscelididae Macroscelidea 67 S T*
35475 Elephantulus rufescens Macroscelididae Macroscelidea 68 T T
34189 Elephantulus rufescens Macroscelididae Macroscelidea 69 T T
39003 Callithrix pygmaea Cebidae Primates 70 A A
39005 Callithrix pygmaea Cebidae Primates 71 A A
75541 Leontopithecus chrysomela Cebidae Primates 72 A A
35406 Saguinus oedipus Cebidae Primates 73 A A
35405 Saguinus oedipus Cebidae Primates 74 A A
82302 Saimiri sciureus Cebidae Primates 75 A A
39014 Saimiri sciureus Cebidae Primates 76 A A
34071 Aplodontia rufa Aplodontiidae Rodentia 77 F Sf*
34058 Aplodontia rufa Aplodontiidae Rodentia 78 F Sf*
34116 Castor canadensis Castoridae Rodentia 79 Sa Sa
34588 Castor canadensis Castoridae Rodentia 80 Sa Sa
72830 Cavia porcellus Caviidae Rodentia 81 T T
72831 Cavia porcellus Caviidae Rodentia 82 T T
76622 Microtus pennsylvanicus Cricetidae Rodentia 83 F F
34326 Microtus pennsylvanicus Cricetidae Rodentia 84 F F
34324 Ondatra zibethicus Cricetidae Rodentia 85 Sa Sa
72879 Ondatra zibethicus Cricetidae Rodentia 86 Sa Sa
66559 Synaptomys borealis Cricetidae Rodentia 87 Sf F*
66561 Synaptomys borealis Cricetidae Rodentia 88 Sf Sf
76721 Zapus princeps Dipodidae Rodentia 89 S Sf*
75136 Zapus princeps Dipodidae Rodentia 90 S S
34176 Coendou prehensilis Erethizontidae Rodentia 91 Sc Sc
44624 Thomomys bottae Geomyidae Rodentia 92 F F
38261 Thomomys bottae Geomyidae Rodentia 93 F F
47378 Chaetodipus fallax Heteromyidae Rodentia 94 F S*
47379 Chaetodipus fallax Heteromyidae Rodentia 95 F A*
78740 Dipodomys deserti Heteromyidae Rodentia 96 S F*
48984 Octodon degus Octodontidae Rodentia 97 Sf A*
39501 Octodon degus Octodontidae Rodentia 98 Sf Sf
35278 Sciurus aberti Sciuridae Rodentia 99 A A
82349 Sciurus aberti Sciuridae Rodentia 100 A A
20646 Sciurus carolinensis Sciuridae Rodentia 101 A A
30010 Sciurus carolinensis Sciuridae Rodentia 102 A A
36334 Glaucomys sabrinus Sciuridae Rodentia 103 G G
35129 Glaucomys sabrinus Sciuridae Rodentia 104 G G
43897 Glaucomys volans Sciuridae Rodentia 105 G G
32254 Glaucomys volans Sciuridae Rodentia 106 G G
75774 Cynomys ludovicianus Sciuridae Rodentia 107 Sf Sf
34227 Tupaia glis Tupaiidae Scandentia 108 A A
34225 Tupaia glis Tupaiidae Scandentia 109 A A

APPENDIX 36.

LDA results and predicted locomotor mode for fossil specimens in this study. Prediction probabilities that are in bold are the top ranked locomotor mode (i.e., rank of 1); all ranks are shown for predictions probabilities, but percentages are shown only for > 0.00%. Abbreviations: Spec. Number, specimen number; Loc. locality; M. morphotype; Bioz., biozone.

Spec.
Number
  Prediction Probabilities Rank
Loc. M. Bioz. A F G S Sa Sc Sf T 1 2 3 4 5 6 7 8
97114 C1115 EuB La 99.39% 0.17%         0.44%   A Sf F T Sc S G Sa
151991 V71203 EuC BCA 27.10% 9.44% 0.02% 0.17%   0.16% 61.01% 2.10% Sf A F T S Sc G Sa
151964 V65127 EuD BCA 0.82% 93.29%   0.04%     5.85%   F Sf A S Sa T G Sc
153036 V65127 EuD BCA 25.36% 23.94%   0.07%     50.54% 0.09% Sf F A T S Sc Sa G
 

TABLE 1. Measurements taken on distal humeri in this study. Columns (from left to right) are: measurements (abbreviation and name); measurement description; taxon of study; and source reference for each measurement. We took the following measurements (Figure 2) on all multituberculate and therian specimens, contingent upon specimen completeness (see Table 2). The anatomical view from which the measurement was taken is indicated in parentheses in the description, as it relates to either multituberculate (Mu) or therian (Th) humeri, see text for more details. Measurements are identical to those in the indicated sources, with the following exceptions: our measurement TDW is ‘BW’ of Szalay and Dagosto (1980) and measurement 5 of Argot (2001); NCW is measurement 6 of Argot (2001) and ‘EEC’ of Boyer et al. (2010); TLW is ‘TLE’ of Szalay and Dagosto (1980); measurements TD and CD are modified from Szalay and Dagosto (1980) and Boyer et al. (2010). Multituberculate measurements lacking references are based on the structurally (but not necessarily functional) analogous measurement for therian humeri (see Figure 2).

Measurements Description Taxon Source
TDW Total Distal Width Medial edge of specimen to lateral edge, measured at the maximum extensions of the entepicondyle and ectepicondyle; parallel to other distal width measures (anterior view in therians; ventral view in multituberculates) Th, Mu Deischl 1964; Szalay and Dagosto 1980; Argot 2001
AW Articular Surface Width Eu: Lateral edge of capitulum to medial edge of trochlea (anterior)

Mu: Lateral edge of radial condyle to medial edge of ulnar condyle (ventral)

Th, Mu Szalay and Dagosto 1980; Szalay and Sargis 2001
TLW Total Lateral Width Eu: Medial edge of trochlea to lateral edge of ectepicondyle (anterior)

Mu: Medial edge of ulnar condyle to lateral edge of ectepicondyle (ventral)

Th, Mu Szalay and Dagosto 1980
NCW Entepicondylar Width Eu: Medial edge of trochlear lip to medial edge of entepicondyle (anterior)

Mu: From midpoint of groove between entepicondyle and ulnar condyle to medial edge of entepicondyle (ventral)

Th, Mu Argot 2001; Boyer et al. 2010
TW Trochlear Width Medial edge of trochlea (trochlear lip) to lateral edge of trochlea (medial edge of intercondylar groove) (anterior) Th Szalay and Dagosto 1980; Boyer et al. 2010
CW Capitulum Width Lateral edge of capitulum to medial edge of intercondylar groove (anterior) Th Szalay and Dagosto 1980; Boyer et al. 2010
TL Trochlear Length Length from proximal margin to distal margin of trochlear lip (anterior) Th Szalay and Dagosto 1980; Boyer et al. 2010
CL Capitulum Length Length from proximal margin to distal margin of capitulum (anterior) Th  this study
TD Trochlear Depth Maximum length from anterior surface to posterior surface of trochlea, parallel to CD (distal) Th Szalay and Dagosto 1980; Boyer et al. 2010
CD Capitulum Depth Length of capitulum articular surface, from anterior to posterior extent, parallel to TD (distal) Th Szalay and Dagosto 1980; Boyer et al. 2010
UCW Ulnar Condyle Width Medial edge of ulnar condyle to lateral edge of ulnar condyle (ventral) Mu  this study
RCW Radial Condyle Width Medial edge of radial condyle to lateral edge of radial condyle (ventral) Mu  this study
UCL Ulnar Condyle Length Length from proximal margin to distal margin of ulnar condyle (ventral) Mu  this study
RCL Radial Condyle Length Length from proximal margin to distal margin of radial condyle (ventral) Mu  this study
UCD Ulnar Condyle Depth Maximum length from ventral surface to dorsal surface ulnar condyle, parallel to RCD (distal) Mu  this study
RCD Radial Condyle Depth Maximum length from ventral surface to dorsal surface radial condyle, parallel to UCD (distal) Mu  this study

 

TABLE 2. Linear measurements of multituberculate distal humeri specimens. See Table 1 for measurement descriptions; all measurements on multituberculate humeri are taken in ventral view except for RCD and UCD, which are taken in distal view. All measurements are in millimeters. Abbreviations: Fm, Formation; HC, Hell Creek Formation; La, Lancian Biozone; Lan, Lance Formation; Morph., Morphotype; Pu1, Puercan 1 Biozone; Pu3, Puercan 3 Biozone; Tu, Tullock Formation. Asterisks indicate minimum size values, where preserved morphology was measured but the full measurement was not possible, due to specimen breakage; “-” indicates specimen was too broken for measurement; “?” indicates more tentative assignment to morphotype, due to specimen breakage. Locality numbers follow the system of each institution; those beginning with “V” are UCMP localities; those beginning with “C” are UWBM localities (see Appendix 1 for additional locality details).

Specimen Locality Fm Biozone Morph. TDW AW TDW NCW UCW RCW UCL RCL UCD RCD
195999 V5620 Lan La MuA 3.695 2.060 2.550 1.045 0.950 1.115 1.365 1.195 1.625 1.525
195974 V65127 Tu BCA MuA 3.995 2.005 2.455 1.255 0.765 1.000 1.305 1.140 1.530 1.510
195982 V65127 Tu BCA MuA - 2.040 2.210 - 0.865 1.170 1.405 1.055 1.445 -
122045 V70201 Tu BCA MuA 4.120 2.105 2.565 1.375 0.875 1.235 1.315 1.165 1.650 1.580
196956 V70201 Tu BCA MuA - 1.960* - - 0.780 1.120* 1.225 1.005 1.275 -
196957 V70201 Tu BCA MuA 3.915 2.090 2.615 1.175 0.840 1.160 1.465 1.240 1.460 1.455
70976 C0338 Tu BCA MuA - 1.850 2.420 - 0.855 1.070 1.345 1.150 1.440 1.400
70977 C0338 Tu BCA MuA 3.695 - 2.580 1.075 1.065 - 1.480 - 1.415 -
195998 V5620 Lan La ?MuA - - - - 0.690 - 0.805 - 1.805 -
153016 V74111 Tu Pu1 ?MuA - 2.165* - - - 1.240 1.475* 1.240* 1.585 1.475*
195933 V99438 Tu Pu3 MuB - - - 1.240 1.080 - 1.465 - 1.670 -
174490 V73087 HC La MuC - 3.555* - - 1.690 2.055 2.440 1.980 2.845 2.445
195997 V5620 Lan La MuC - 2.525 3.150 - 0.985 1.360 1.925 1.600 2.145 2.000
174420 V70209 Tu BCA MuC 5.290 2.975 3.595 1.480 1.295 1.630 1.975 2.030* 2.130 1.975
153039 V84193 HC Pu1 MuC 6.460 3.090 4.250 1.960 1.570 1.700 2.185 1.830 2.555 2.335
197687 V74111 Tu Pu1 MuC - 3.565* - - 1.480* 2.050* 2.240 1.885 2.330 -
195932 V99438 Tu Pu3 MuC 5.350* 3.035 3.820 1.460* 1.505 1.640 2.180 1.765 2.515 2.295
195945 V74122 Tu Pu3 MuC 5.590* 3.040 3.815 1.480 1.270 1.420 2.455 1.755 2.345 2.305
195990 V5620 Lan La MuD 7.310* 4.230* 5.470* 1.835* - 2.160 - 2.135 - 2.350
174439 V70209 Tu BCA MuE - - - 2.385 1.855 - 3.265 - 3.200 -
174442 V70209 Tu BCA MuE - - - - 1.965 - 2.730* - 2.600* 2.680
195973 V65127 Tu BCA MuE 8.130 4.025 5.080 2.445 1.485 2.410 2.810 2.265 3.200 3.145
97031 C1845 Tu BCA MuE 8.420 4.400 5.230 2.595 2.000 2.565 2.695 2.485 3.355 3.335
174412 V84162 HC Pu1 MuE - - - - 2.360 - 3.535 - 3.910 -
127384 V87001 HC La MuF 14.025 7.730 9.990 3.970 3.865 4.435 5.440 5.095 6.420 5.580
174400 V85092 HC La MuF - 6.900 - - 3.135 3.945 4.985 4.260 5.180 4.530
174232 V72207 HC La MuF - - - - - 5.050 - 5.655 - 6.365
174225 V72207 HC La MuF - 6.815* - 3.255 3.435 4.215* 5.045 4.900 5.835 -
174218 V73097 HC La MuF - 7.820* - - 2.450 4.325 5.605 5.145 6.420 -
101970 C1521 HC La MuF 13.705 6.945 9.105 3.995 2.985 3.915 5.030 3.900 5.030 4.405

 

 

TABLE 3. Linear measurements of therian distal humeri specimens. See Table 1 for measurement descriptions; all measurements on therian humeri are taken in anterior view except for CD and TD, which are taken in distal view . All measurements are in millimeters. Abbreviations: Fm, Formation; HC, Hell Creek Formation; La, Lancian Biozone; Morph., Morphotype; Pu1, Puercan 1 Biozone; Pu3, Puercan 3 Biozone; Tu, Tullock Formation. Asterisks indicate minimum size values, where preserved morphology was measured but the full measurement was not possible, due to specimen breakage; “-” indicates specimen was broken; “?” indicates more tentative assignment to morphotype; “‡” indicates specimen was used in 2D GM locomotor analyses.Locality numbers follow the system of each institution: those beginning with “V” are UCMP localities; those beginning with “C” are UWBM localities (see Appendix 1 for additional locality details). Five additional specimens from the BCA biozone (UCMP 151945, 151965, 151983, and 151984 from loc. V65127, and UCMP 174429 from loc. V70209) are tentatively attributed to EuD but are not listed below as they lack preservation sufficient for measurement, see text for more details.

Specimen Locality Fm Biozone Morph. TDW AW TLW NCW TW CW TL CL TD CD
127391 V88007 HC La ThA 4.900* - - 2.380 1.210 - 1.340 - 1.380 -
152394 V93169 HC La MeA 18.235* - - - - - - - - -
153100 V99438 Tu Pu3 EuA 6.400* 3.850 3.850 2.900* 1.330 2.406 1.630 1.579 1.756 1.920
97114‡ C1115 HC La EuB 8.53* 4.765 5.120 3.400* 1.705 2.895 1.960 1.945 2.355 2.335*
151991‡ V71203 HC BCA EuC 9.520 5.635 5.735 3.820 1.670 3.945 2.680 2.515 3.030 3.310
153023 V74111 Tu Pu1 EuC - - - 4.015 1.510* - 2.500* - 3.160 -
151985 V70201 Tu BCA EuD 7.810* 5.295 5.285 - 1.890 3.255 2.175 .720 2.235 2.495
151944 V65127 Tu BCA EuD 8.845* 5.735 6.005 2.190* 2.185 3.655 1.940 2.320 2.230* 2.575*
151946 V65127 Tu BCA EuD 8.800* 5.270 6.060 - 1.970 3.255 1.665 2.080 2.185 2.510*
151964‡ V65127 Tu BCA EuD 9.225 5.340 5.700 3.550 1.750 3.585 1.645 2.005 2.225 2.380
153036‡ V65127 Tu BCA EuD 9.935 5.675 5.850 4.210 1.820 3.800 1.775 2.155 2.470 2.710
218901 V91065 Tu Pu1 EuE 17.925* 10.685 10.850 7.175* 2.950 7.620 4.575 5.110 6.280 7.525
92928 C1163 Tu Pu3 EuE 15.030* 9.550 9.700 - 2.640 6.960 4.330 4.580 5.120* 5.320
153089 V72129 Tu Pu3 EuF 19.415* 17.280 17.395 - 5.480 11.820 6.945 7.280 8.735* 9.670
192678 V72124 Tu Pu3 EuG - - - 10.300 5.095 - 7.435 - 9.425* -

 

 

TABLE 4. Modern mammalian specimens used in geometric morphometrics analyses. Species list and locomotor references are modified from Chen and Wilson 2015; see text for more details. All specimens are from the UWBM except for those with specimen numbers A2001 and S2008, which are taken from images of specimens in distal view in Argot (2001, figure 8) and Salton and Sargis (2008, figure 4.10), respectively. Code number assigned (and table sorted) as follows: clade, order, family, and locomotor mode. Locomotor mode abbreviations are as follows: A, arboreal; F, fossorial; G, gliding; S, saltatorial; Sa, semiaquatic; Sc, scansorial; Sf, semifossorial; T, terrestrial. Other abbreviations: F, female; LM, locomotor mode; M, male; Spec., specimen number; U, sex unknown.

Clade Order Code LM Genus Species Family Spec. Sex Locomotor Reference
Metatheria
  Dasyuromorphia
    1 T Antechinus swainsonii Dasyuridae 68900 M Nowak 1999
    2 T Sarcophilus harrisii Dasyuridae 20671 M Van Valkenburgh 1987
  Didelphimorphia
    3 A Caluromys philander Didelphidae A2001 U Argot 2001; Nowak 1999
    4 A Caluromys derbianus Didelphidae 32255 U Argot 2001
    5 A Micoureus demerarae Didelphidae A2001 U Argot 2001
    6 Sc Didelphis virginiana Didelphidae 35525 F Argot 2001
    7 Sc Didelphis virginiana Didelphidae 74661 M Argot 2001
    8 Sc Didelphis marsupialis Didelphidae A2001 U Argot 2001; Nowak 1999
    9 Sc Marmosa murina Didelphidae A2001 U Argot 2001; Nowak 1999
    10 T Metachirus nudicaudatus Didelphidae 35438 F Argot 2001; Delciellos and Vieira 2006
    11 T Monodelphis brevicaudata Didelphidae A2001 U Argot 2001; Nowak 1999
  Diprotodontia
    12 G Petaurus breviceps Petauridae 34181 M Smith 1973; Nowak 1999; Körtner and Geiser 2000
    13 G Petaurus breviceps Petauridae 72928 U Smith 1973; Nowak 1999; Körtner and Geiser 2000
    14 A Trichosurus vulpecula Phalangeridae 68913 M Nowak 1999
    15 S Potorous tridactylus Potoroidae 41025 F Bassarova et al. 2009
    16 S Potorous tridactylus Potoroidae 34200 M Bassarova et al. 2009
    17 S Aepyprymnus rufescens Potoroidae 68898 F Bassarova et al. 2009
    18 A Pseudocheirus peregrinus Pseudocheiridae 68924 F Bassarova et al. 2009
    19 A Pseudocheirus peregrinus Pseudocheiridae 68908 M Bassarova et al. 2009
  Peramelemorphia
    20 T Perameles nasuta Peramelidae 68919 F Nowak 1999
Eutheria
  Afrosoricida
    21 Sa Potamogale velox Potamogalidae S2008 U Nowak 1999; Salton and Sargis 2008
    22 A Dendrohyrax arboreus Procaviidae 39039 F Nowak 1999
    23 A Dendrohyrax arboreus Procaviidae 39038 M Nowak 1999
    24 Sa Limnogale mergulus Tenrecidae S2008 U Nowak 1999; Salton and Sargis 2008
    25 Sc Echinops telfairi Tenrecidae 34168 F Endo et al. 2006; Salton and Sargis 2008
    26 Sc Echinops telfairi Tenrecidae S2008 U Endo et al. 2006; Salton and Sargis 2008
    27 Sf Hemicentetes semispinosus Tenrecidae S2008 U Nowak 1999; Salton and Sargis 2008
    28 Sf Oryzorictes sp. Tenrecidae S2008 U Nowak 1999; Salton and Sargis 2008
    29 T Setifer setosus Tenrecidae S2008 U Salton and Sargis 2008
    30 T Tenrec ecaudatus Tenrecidae S2008 U Salton and Sargis 2008
    31 T Microgale cowani Tenrecidae S2008 U Nowak 1999; Salton and Sargis 2008
    32 T Microgale dobsoni Tenrecidae S2008 U Nowak 1999; Salton and Sargis 2008
    33 T Microgale talazaci Tenrecidae S2008 U Nowak 1999; Salton and Sargis 2008
  Carnivora
    34 T Vulpes vulpes Canidae 39490 F Lariviére and Pasitschniak-Arts 1996; Meachen-Samuels 2010
    35 T Vulpes vulpes Canidae 39489 M Lariviére and Pasitschniak-Arts 1996; Meachen-Samuels 2010
    36 Sc Urocyon cinereoargenteus Felidae 77676 F Van Valkenburgh 1987; Meachen-Samuels 2010
    37 Sc Urocyon cinereoargenteus Felidae 35221 M Van Valkenburgh 1987; Meachen-Samuels 2010
    38 Sc Suricata suricatta Herpestidae 35470 F van Staaden 1994; Iwaniuk et al. 1999
    39 Sc Suricata suricatta Herpestidae 35469 M van Staaden 1994; Iwaniuk et al. 1999
    40 Sf Mephitis mephitis Mephitidae 35951 F Wade-Smith and Verts 1982; Van Valkenburgh 1987; Samuels and Van Valkenburgh 2008
    41 Sf Mephitis mephitis Mephitidae 39321 M Wade-Smith and Verts 1982; Van Valkenburgh 1987; Samuels and Van Valkenburgh 2008
    42 Sa Lontra canadensis Mustelidae 32226 F Gingerich 2003
    43 Sa Lontra canadensis Mustelidae 32230 M Gingerich 2003
    44 Sa Mustela vison Mustelidae 41780 F Howell 1930; Larivié́re 1999; Gingerich 2003
    45 Sa Mustela vison Mustelidae 35223 M Howell 1930; Larivié́re 1999; Gingerich 2003
    46 Sc Gulo gulo Mustelidae 14200 F Van Valkenburgh 1987; Pasitschniak-Arts and Larivié́re 1995
    47 Sc Gulo gulo Mustelidae 34417 M Van Valkenburgh 1987; Pasitschniak-Arts and Lariviére 1995
    48 Sf Spilogale putorius Mustelidae 39331 F Heinrich and Houde 2006
    49 Sf Spilogale putorius Mustelidae 39155 M Heinrich and Houde 2006
    50 T Mustela erminea Mustelidae 39366 F Nowak 1999
    51 T Mustela erminea Mustelidae 72863 M Nowak 1999
    52 T Mustela putorius Mustelidae 32599 F Nowak 1999
    53 T Mustela putorius Mustelidae 58727 M Nowak 1999
    54 A Paguma larvata Viverridae 73281 U Nowak 1999
  Cingulata
    55 F Cabassous centralis Dasypodidae 34167 F Nowak 1999
  56 F Dasypus novemcinctus Dasypodidae 20735 F Samuels and Van Valkenburgh 2008
  57 F Dasypus novemcinctus Dasypodidae 22458 M Samuels and Van Valkenburgh 2008
  58 F Euphractus sexcinctus Dasypodidae 35468 M Redford and Wetzel 1985; Nowak 1999
  Eulipotyphla
    59 T Echinosorex gymnurus Erinaceidae S2008 U Nowak 1999; Salton and Sargis 2008
  60 Sf Solenodon paradoxus Solenodontidae S2008 U Nowak 1999; Salton and Sargis 2008
  Lagomorpha
    61 S Brachylagus idahoensis Leporidae 38628 F Nowak 1999
  62 S Brachylagus idahoensis Leporidae 38631 M Nowak 1999
  63 S Lepus americanus Leporidae 21111 F Nowak 1999
  64 S Lepus americanus Leporidae 33263 M Nowak 1999
  65 Sf Ochotona princeps Ochtonidae 18435 F Nowak 1999
  66 Sf Ochotona princeps Ochtonidae 60068 M Nowak 1999
  Macroscelidea
    67 S Petrodromus tetradactylus Macroscelididae S2008 U Salton and Sargis 2008
  68 T Elephantulus rufescens Macroscelididae 35475 F Nowak 1999
  69 T Elephantulus rufescens Macroscelididae 34189 M Nowak 1999
  Primates
    70 A Callithrix pygmaea Cebidae 39003 F Nowak 1999
  71 A Callithrix pygmaea Cebidae 39005 M Nowak 1999
  72 A Leontopithecus rosalia Cebidae 75541 F Nowak 1999
  73 A Saguinus oedipus Cebidae 35406 F Nyakatura et al. 2008
  74 A Saguinus oedipus Cebidae 35405 M Nyakatura et al. 2008
  75 A Saimiri sciureus Cebidae 82302 F Nowak 1999
  76 A Saimiri sciureus Cebidae 39014 M Nowak 1999
  Rodentia
    77 F Aplodontia rufa Aplodontiidae 34071 F Samuels and Van Valkenburgh 2008
    78 F Aplodontia rufa Aplodontiidae 34058 M Samuels and Van Valkenburgh 2008
    79 Sa Castor canadensis Castoridae 34116 F Nowak 1999
    80 Sa Castor canadensis Castoridae 34588 M Nowak 1999
    81 T Cavia porcellus Caviidae 72830 F Nowak 1999
    82 T Cavia porcellus Caviidae 72831 M Nowak 1999
    83 F Microtus pennsylvanicus Cricetidae 76622 F Nowak 1999
    84 F Microtus pennsylvanicus Cricetidae 34326 M Nowak 1999
    85 Sa Ondatra zibethicus Cricetidae 34324 F Howell 1930; Gingerich 2003
    86 Sa Ondatra zibethicus Cricetidae 72879 M Howell 1930; Gingerich 2003
    87 Sf Synaptomys borealis Cricetidae 66559 F Nowak 1999
    88 Sf Synaptomys borealis Cricetidae 66561 M Nowak 1999
    89 S Zapus princeps Dipodidae 76721 F Nowak 1999
    90 S Zapus princeps Dipodidae 75136 M Nowak 1999
    91 Sc Coendou prehensilis Erethizontidae 34176 F Nowak 1999
    92 F Thomomys bottae Geomyidae 44624 F Nowak 1999
    93 F Thomomys bottae Geomyidae 38261 M Nowak 1999
    94 F Chaetodipus fallax Heteromyidae 47378 F Lackey 1996
    95 F Chaetodipus fallax Heteromyidae 47379 M Lackey 1996
    96 S Dipodomys deserti Heteromyidae 78740 F Samuels and Van Valkenburgh 2008
    97 Sf Octodon degus Octodontidae 48984 F Nowak 1999
    98 Sf Octodon degus Octodontidae 39501 M Nowak 1999
    99 A Sciurus aberti Sciuridae 35278 F Nowak 1999
    100 A Sciurus aberti Sciuridae 82349 M Nowak 1999
    101 A Sciurus carolinensis Sciuridae 20646 F Nowak 1999
    102 A Sciurus carolinensis Sciuridae 30010 M Nowak 1999
    103 G Glaucomys sabrinus Sciuridae 36334 F Samuels and Van Valkenburgh 2008
    104 G Glaucomys sabrinus Sciuridae 35129 M Samuels and Van Valkenburgh 2008
    105 G Glaucomys volans Sciuridae 43897 F Nowak 1999
    106 G Glaucomys volans Sciuridae 32254 M Nowak 1999
    107 Sf Cynomys ludovicianus Sciuridae 75774 M Nowak 1999
  Scandentia
    108 Sc Tupaia glis Tupaiidae 34227 F Van Valkenburgh 1987
    109 Sc Tupaia glis Tupaiidae 34225 M Van Valkenburgh 1987

 

 

TABLE 5. Landmark number, location, type, and source reference for two-dimensional geometric morphometrics (2D GM) points on therian distal humeri. All points were digitized on distal images of specimens; see Figure 3 for more details. Numbers in parentheses are the landmark number for the point within the referenced source. Abbreviations: LM, landmark; Type, landmark type according to Zelditch et al. 2004.

LM Location Type Source Reference
1 Lateral point on the posterior trochlea II Steiner-Souza et al. 2010
2 Medial point on the posterior trochlea II Steiner-Souza et al. 2010
3 Medial point on the anterior trochlea II Steiner-Souza et al. 2010
4 Lateral point on the anterior capitulum II Steiner-Souza et al. 2010
5 Most lateral point on the ectepicondyle III Schutz and Guralnick 2007 (5); Steiner-Souza et al. 2010
6 Most medial point on the entepicondyle III Milne et al. 2009 (12); Steiner-Souza et al. 2010
 

FIGURE 1. Map of humerus-bearing fossil localities from this study. Localities span the Lancian biozone (yellow circles), and early and late Puercan biozones (Pu1 and Pu3, in blue stars and green triangles, respectively), as well as the temporally mixed Lancian-Pu1 localities of the Bug Creek Anthills (red squares). Most localities are in Garfield and McCone counties; Fallon and Carter counties in Montana and Niobrara County in eastern Wyoming (not pictured) each have one locality. Locality names and details are given in Appendix 1. Modified from Wilson et al. 2014.

 figure1a

FIGURE 2. Schematic of humerus measurements used in this study. Multituberculate specimen (UCMP 153039; left) in ventral (1), dorsal (2), and distal (3) views; eutherian specimen (UCMP 151964; right, reversed to appear as left) in anterior (4), posterior (5), and distal (6) views. See Table 1 for measurement descriptions. Abbreviations: AW, articular width; C, capitulum; CL, capitulum length; CD, capitulum depth; CW, capitulum width; EC, ectepicondyle; LC, lateral epicondyle (ectepicondyle); MC, medial epicondyle (entepicondyle); NC, entepicondyle; NCW, entepicondylar width; RC, radial condyle; RCL, radial condyle length; RCD, radial condyle depth; RCW, radial condyle width; TDW, total distal width; TL, trochlear length; TD, trochlear depth; TLW, total lateral width; TW; trochlear width; UC, ulnar condyle; UCL, ulnar condyle length; UCD, ulnar condyle depth; UCW, ulnar condyle width; UT, ulnar trochlea.

 figure2

FIGURE 3. Geometric morphometric scheme and method for placement of landmarks (LMs), curves, and semilandmarks (SLMs) on therian left distal humerus (UWBM 20646, Sciurus carolinensis). All specimens were oriented with anterior up and medial to the left; right specimens were reflected to appear as lefts. (1) LMs 1-6 were plotted (see Table 5 for landmark descriptions). (2) Curves were traced along the anterior, posterior, and medial borders of the articular surface. (3) Curves were re-sampled for equivalent lengths between points, with 11, nine, and five points describing the anterior, posterior, and medial borders of the articular surface, respectively. All resampled points and LMs were used for Procrustes superimposition, with sliders (gray) allowed to slide between helper points (white; see Methods). (4) Helpers were deleted, and all remaining LMs (black) and SLMs (white) were used in PCA analyses.

 figure3

FIGURE 4. Multituberculate morphotype MuA (UCMP specimen 122045, from locality V70201; right), in ventral (1) and dorsal (2) stereopair views, and in lateral (3), medial (4), and distal (5) views.

 figure4

FIGURE 5. Multituberculate morphotype MuB (UCMP specimen 195933, from locality V99438; left), in ventral (1) and dorsal (2) stereopair views, and in distal (3), medial (4), and lateral (5) views.

 figure 5

FIGURE 6. Multituberculate morphotype MuC (UCMP specimen 153039, from locality V84193; left), in ventral (1) and dorsal (2) stereopair views, and in lateral (3), medial (4), and distal (5) views.

 figure 6

FIGURE 7. Multituberculate morphotype MuD (UCMP specimen 195990, from locality V5620; left), in ventral (1) and dorsal (2) stereopair views, and in medial (3), lateral (4), and distal (5) views.

figure 7a
 

FIGURE 8. Multituberculate morphotype MuE (UWBM specimen 97031, from locality C1845; right), in ventral (1) and dorsal (2) stereopair views, and in lateral (3), medial (4), and distal (5) views.

 figure8

FIGURE 9. Multituberculate morphotype MuF (UCMP specimen 127384, from locality V87001; left), in ventral (1) and dorsal (2) stereopair views, and in lateral (3), medial (4), and distal (5) views.

 

FIGURE 10. Therian morphotype ThA (UCMP specimen 127391, from locality V88007; left) in anterior (1) and posterior (2) stereopair views, and in medial (3) view.

 figure 10

FIGURE 11. Metatherian morphotype MeA (UCMP specimen 152394, from locality V93169; left) in anterior (1) and posterior (2) stereopair views, and in lateral (3), medial (4), and distal (5) views.

 figure 11

FIGURE 12. Eutherian morphotype EuA (UCMP specimen 153100, from locality V99438; left) in anterior (1) and posterior (2) stereopair views, and in lateral (3), medial (4), and distal (5) views. Specimen images are CT scan views, not photographs; see Methods for details. Rough patches inside the shaft and within the entepicondylar foramen are the result of sediment infilling, whereas other rough areas (i.e., supinator crest, medial entepicondyle, posterior articular surfaces) indicate specimen breakage.

 figure 12

FIGURE 13. Eutherian morphotype EuB (UWBM specimen 97114, from locality C1115; left) in anterior (1) and posterior (2) stereopair views, and in distal (3), lateral (4), and medial (5) views.

 figure 13

FIGURE 14. Eutherian morphotype EuC (UCMP specimen 151991, from locality V71203; right) in anterior (1) and posterior (2) stereopair views, and in lateral (3), medial (4), and distal (5) views.

 figure 14

FIGURE 15. Eutherian morphotype EuD (UCMP specimen 151964, from locality V65127; right) in anterior (1) and posterior (2) stereopair views, and in lateral (3), medial (4), and distal (5) views.

 figure 15

FIGURE 16. Eutherian morphotype EuE (UCMP specimen 218901, from locality V91065; right) in anterior (1) and posterior (2) stereopair views, and in lateral (3), medial (4), and distal (5) views.

 figure 16

FIGURE 17. Eutherian morphotype EuF (UCMP specimen 92928, from locality V72129; right) in anterior (1) and posterior (2) stereopair views, and in lateral (3), medial (4), and distal (5) views.

 figure 17

FIGURE 18. Eutherian morphotype EuG (UCMP specimen 192678, from locality V74124; left) in anterior (1) and posterior (2) stereopair views, and in medial (3) and distal (4) views.

FIGURE 19. Summary of humerus morphotypes and relative sizes in our study area in the Hell Creek and Tullock formations of eastern Montana. Multituberculate morphotypes are shown as black bars, metatherians as gray bars, and eutherians as white bars. Numbers within the bars indicate the sample size for each temporal bin. Morphotypes are arranged left to right according to increasing size (see text for specimen numbers, localities, and details; Appendix 7-Appendix 8 for morphotype mean sizes). Gradients for MuF, EuC, and EuD indicate morphotypes were present in the time-averaged Bug Creek Anthills assemblages, and the morphotype range may extend into the Pu1 and/or the Lancian. Pu2 assemblages are not known from our study area (hashmarks indicate resultant uncertainty of range-through morphotypes; Clemens 2015). The age model is based on previous geochronological work in this study area (Swisher et al., 1993; Renne et al., 2011, 2013; Wilson, 2014; Sprain et al. 2014); note the temporal axis is not to scale. Modified from Sprain et al. (2014). Abbreviations: Fm, Formation; NALMA, North American Land Mammal “age”; Pu1, early Puercan; Pu3, middle/late Puercan; queries (?) indicate specimens that are only tentatively attributed to that morphotype, see Methods.

 figure 19

FIGURE 20. Plots of Principal Component Analysis (PCA) of full dataset, color-coded for taxon (top) and locomotor group (bottom), with fossils (open circles) projected into the morphospace. (1) PC1 vs. PC2 and (2) PC2 vs. PC3 for all taxa (legend top right), and the same data for locomotor group (3-4; legend bottom right). Also included are the deformation grids for the extreme ends of PC1 and PC2 on right humerus in distal view (identical to Appendix 32-Appendix 33).

 figure 20

FIGURE 21. Plots of PCA of pruned dataset, color-coded for taxon (top) and locomotor group (bottom), with fossils (open circles) projected into the morphospace. (1) PC1 vs. PC2 and (2) PC2 vs. PC3 for all taxa (legend top right), and the same data for locomotor group (3-4; legend bottom right). Also included are the deformation grids for the extreme ends of PC1 and PC2.

 figure 21

FIGURE 22. Plot of PC1 vs. PC2 for the pruned dataset with (1-8) each locomotor group plotted separately (data, legend, and fossil placement identical to Figure 21.3).

figure 22 

FIGURE 23. Plot of PC2 vs. PC3 for the pruned dataset with (1-8) each locomotor group plotted separately (data, legend, and fossil placement identical to Figure 21.4).

 figure 23

FIGURE 24. Plots of Linear Discriminant Analysis of the pruned dataset according to locomotor group. (1) LD1 vs. LD2; (2) LD1 vs. LD3; and (3) LD2 vs. LD3.

figure 24

 

 

debeyLauren B. DeBey. Department of Biology, University of Washington, Box 351800, Seattle, WA 98195-1800, USA. Burke Museum of Natural History and Culture, Box 353010, Seattle, WA 98195-0001, USA. This email address is being protected from spambots. You need JavaScript enabled to view it.

Lauren DeBey received her PhD from the Biology Department at the University of Washington, where she focused on mammalian postcrania across the Cretaceous-Paleogene boundary of northeastern Montana. She co-founded a professional development program called the Discoveries in Geosciences (DIG) Field School, which provides immersive field experiences and curriculum support for K-12 STEM teachers. She is currently a Product Consultant at Tableau Software in Seattle, Washington.

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wilsonGregory P. Wilson. Department of Biology, University of Washington, Box 351800, Seattle, WA 98195-1800, USA. Burke Museum of Natural History and Culture, Box 353010, Seattle, WA 98195-0001, USA. This email address is being protected from spambots. You need JavaScript enabled to view it.

Greg Wilson is a vertebrate paleontologist who specializes in Mesozoic and early Cenozoic mammals and the Cretaceous-Paleogene mass extinction event. He has conducted field research in India, Colombia, Ethiopia, Niger, Mexico, and the United States. He co-founded a professional development program called the Discoveries in Geosciences (DIG) Field School, which provides immersive field experiences and curriculum support for K-12 STEM teachers. Greg is currently an Associate Professor of Biology at the University of Washington and Curator of Vertebrate Paleontology at the Burke Museum. His wife, Caroline Stromberg, and brother, Jeff Wilson, are also paleontologists.