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Systematics and dental microwear of the late Miocene Gliridae (Rodentia, Mammalia) from Hayranlı, Anatolia: implications for paleoecology and paleobiodiversity

Ferhat Kaya and Nuretdin Kaymakçı

Plain Language Abstract

The Dormouse family is one of the oldest groups of rodents that first appeared around 40 million years ago in Europe. They dispersed widely between 20 and 8 million years ago, diversified into a number of species, occupying different habitats in Europe, Asia, and Africa. Anatolia, as a geographical bridge among these continents, has various localities that have yielded important fossil remains of dormouse ranging from Oligocene to recent times. Hayranlı is one of these localities. It dates back around 8 million years to the site where two different dormouse genera were recovered. One of these dormouse genera is an extinct genus, Microdyromys koenigswaldi and is most probably an ancestor to the living forest dormouse. The other, Myomimus maritsensis, is an extinct species that resembles the living tailed dormouse. Understanding an animal's diet provides key insights about habitat and ecological relationships in nature. As an alternative way of inferring paleodiet, we investigate microwear patterns (scratches and pits) on the surface of lower second molars on both species. This analysis indicates that these species of dormouse had a diet that involved a combination of insects, fruit, seeds, and grasses —pointing to a more generalist behavioral adaptation to the seasonal availability of foods. Environmental changes that occurred 20 to 10 million years ago in Eurasia caused a drastic decrease in the number of dormouse. Also as a result of these changes, significant faunal exchange from forest dwellers to ground dweller species occurred 10 to 5 million years ago in the Eastern Mediterranean.

Özet in Turkish

İç Anadolu Bölgesi'nin doğusunda yer alan ve Geç Miyosen döneme tarihlendirilen Hayranlı (Sivas) lokalitesinden bulunmuş Gliridae (Mammalia, Rodentia) ailesine ait yeni buluntular tanımlanmıştır. Tanımlanan materyal Microdyromys koenigswaldi De Bruijn, 1966 ve Myomimus maritsensis De Bruijn et al., 1970 türlerinden oluşmaktadır. Myomimus ve Peridyromys' in paylaştığı morfolojik benzerliklerden dolayı bu iki cinse ait fosil materyali birbirinden ayırmak güçtür. Microdyromys cinsi son olarak Ampudia 3 (MN 10, Duero Basin, Spain) lokalitesinden kaydedilmişti, ancak Orta Turoliyen döneme tarihlendirilen Hayranlı lokalitesi koleksiyonu bu tarihi günümüze daha yakın bir döneme çekmiştir. Dişler üzerinde yapılan mikro-aşınma analizi Hayranlı yediuyur türlerinin böcek, meyve, tohum ve ot gibi çeşitli besinlerin bir kombinasyonu ile beslendiğini, ayrıca bu tür beslenme biçimini besinlerin mevsimselliğine bağlı olarak daha genelci bir stratejiye uyum sağladıklarını göstermektedir. Orta Miyosen ve Geç Miyosen dönemler arasında Avrupa ve Doğu Akdeniz'de meydana gelen çevresel değişimler ağaç yaşamına, sıcak ve nemli iklime uyum sağlamış Gliridae ailesinin üyelerinin sayısal olarak ciddi bir derecede azalmasına neden oldu. Muhtemelen orman ve bataklık çevrelerde yaşayan bitki topluluklarının yerini açık alan bitkilerine bırakması beraberinde bu ailenin ağaçlarda yaşayan türlerinin yerde yaşayan türlere doğru faunal evrimi Geç Miyosen'de artan Myomimus buluntuları ile karakterize olmuştur. Hayranlı lokalitesinden keşfedilen otçul-hepçil büyük memeli buluntularına bağlı olarak ortalama hypsodonty değeri (=1.6) görece nemli, ağaçlık ve çalılık bir paleoekolojinin varlığını betimlemektedir.

Translation by authors

Resumen en Español

Sistemática y microdesgaste dental de los Gliridae (Rodentia, Mammalia) del Mioceno tardío de Hayranlı, Anatolia: implicaciones en la paleoecología y paleobiodiversidad

Se describen nuevos hallazgos de Gliridae (Mammalia, Rodentia) del Mioceno tardío de Hayranlı, en la parte central de Anatolia oriental. Los ejemplares encontrados corresponden a Microdyromys koenigswaldi De Bruijn, 1966 y Myomimus maritsensis De Bruijn et al., 1970. El solapamiento morfológico entre Myomimus y Peridyromys dificulta la distinción entre los dos géneros. La última aparición de Microdyromys había sido registrada anteriormente en la localidad de Ampudia 3 (MN 10, cuenca del Duero, España), pero los ejemplares de Hayranlı del Turoliense medio extienden su distribución espacio-temporal. El análisis de microdesgaste dental indica que la dieta de estas especies de lirones incluía insectos, frutos, semillas y hierbas, lo que apuntaría al desarrollo de un comportamiento más generalista adaptado a la disponibilidad estacional de alimentos. Los cambios ambientales que ocurrieron desde el Mioceno medio al Mioceno tardío en Europa y el Mediterráneo oriental provocaron un drástico descenso en el número de especies de Gliridae adaptadas a un modo de vida arborícola y a un clima cálido y húmedo. Hay un significativo cambio faunístico de habitantes de los bosques a formas que viven sobre el suelo, que se traduce en un aumento de los hallazgos de Myomimus en varias localidades durante el Mioceno tardío, probablemente atribuible a un cambio en la vegetación desde ambientes de humedales boscosos a ambientes de bosques abiertos y de estepa. El valor medio de hipsodoncia (=1.6) de la amplia colección de mamíferos herbívoros y omnívoros de Hayranlı indica un paleoambiente de bosques claros relativamente húmedos y con abundante matorral.

Palabras clave: Gliridae; microdesgaste; Mioceno tardío; Anatolia; paleoecología; paleobiodiversidad

Traducción: Miguel Company

Résumé en Français

Systématique et usure dentaire de la famille Gliridae (Rodentia, Mammalia) de la fin du Miocène de Hayranlı, l'Anatolie: implications pour la paléoécologie et paléobiodiversité

De nouvelles découvertes de la famille Gliridae (Mammalia, Rodentia) de la fin du Miocène de Hayranlı, situé dans le centre de l'Anatolie orientale, sont décrites. Ces spécimens comprennent Microdyromys koenigswaldi De Bruijn, 1966, et Myomimus maritsensis De Bruijn et al., 1970. Les chevauchements morphologiques entre Myomimus et Peridyromys rendent la distinction entre les deux genres difficiles. La dernière apparition de Microdyromys a déjà été enregistrée à Ampudia 3 (MN 10, le bassin de Duero, Espagne), mais les collections de Hayranlı du milieu du Turolien étendent son apparition spatio-temporelle. L'analyse de micro-usure dentaire indique que ces espèces de loirs ont un régime alimentaire qui comportait une combinaison d'insectes, de fruits, de graines et d'herbes, ce qui pourrait indiquer le développement d'un comportement plus généraliste adapté à la disponibilité saisonnière des aliments. Les changements environnementaux, survenant entre le Miocène moyen et la fin du Miocène en Europe et en Méditerranée orientale, ont provoqué une diminution drastique du nombre d'espèces de la famille Gliridae adaptées à un mode de vie arboricole et à un climat chaud et humide. Il y a un changement faunistique important remplaçant les espèces forestières par des espèces vivant au sol, caractérisée par l'augmentation de découvertes d'espèces de Myomimus provenant d'un certain nombre de localités de la fin du Miocène - probablement attribuables au changement de végétation remplaçant les environnements avec une prédominance de milieux humides boisées par des forêts ouvertes et des steppes. En prenant compte des collections de Hayranlı de grand mammifère herbivore-omnivore, la valeur moyenne d'hypsodontie (= 1.6) dépeint un paléoenvironnement avec des forêts relativement humides et arbustives.

Mots-clés: Gliridae; micro-usure; fin du Miocène; Anatolie; paléoécologie; paléobiodiversité

Translator: Kenny J. Travouillon

Deutsche Zusammenfassung

Systematik und Dental-Microwear der spätmiozänen Gliridae (Rodentia, Mammalia) aus Hayranlı, Anatolien: Auswirkungen auf die Paläoökologie und Paläobiodiversität

Es werden neue Funde von Gliridae (Mammalia, Rodentia) aus dem späten Miozän von Hayranlı, gelegen in Zentralostanatolien, beschrieben. Diese Stücke beinhalten Microdyromys koenigswaldi De Bruijn, 1966 und Myomimus maritsensis De Bruijn et al., 1970. Die morphologische Überlappung zwischen Myomimus und Peridyromys erschwert eine Unterscheidung zwischen den beiden Gattungen. Nach bisherigem Stand trat Microdyromys zuletzt in Ampudia 3 (MN 10, Duero Becken, Spanien) auf, jedoch erweitert die Hayranlı-Kollektion aus dem mittleren Turon das raumzeitliche Auftreten. Dental-Microwear-Analyse weist darauf hin, dass sich diese Haselmaus-Art von einer Mischung aus Insekten, Früchten, Samen und Gräsern ernährte, was auf die Entwicklung einer eher generalisierten Verhaltensweise hindeutet, die auf die saisonale Verfügbarkeit von Nahrung zugeschnitten ist.

Umweltveränderungen, die ab dem mittleren Miozän bis zum späten Miozän in Europa und im östlichen Mittelmeerraum auftraten, bewirkten einen drastischen Rückgang der Artenzahl der Gliridae die an eine arboreale Lebensweise und ein warmes und humides Klima angepasst waren. Es gibt einen signifikanten Faunenaustausch zwischen waldbewohnenden und bodenlebenden Arten, der durch einen Anstieg an Funden von Myomimus aus einer Reihe von Fundstätten während des späten Miozän gekennzeichnet ist. Dies hängt möglicherweise mit einer Verschiebung der Vegetationszonen von einem überwiegend bewaldeten Sumpfgebiet hin zu offenen Wäldern und Steppe-ähnlicher Umgebung zusammen. Entsprechend der großen Sammlung an herbivor-omnivoren Säugetieren von Hayranlı weist der Haupt-Hypsodontie-Wert (=1.6) auf eine relativ humide bewaldete und buschige Paläoumwelt hin.

Schlüsselwörter: Gliridae; Microwear; spätes Miozän; Anatolien; Paläoökologie; Paläobiodiversität

Translator: Eva Gebauer

Arabic

385 arab

Translator: Ashraf M.T. Elewa

 

 

TABLE 1. Material and measurements of Myomimus maritsensis from Hayranlı locality.

 

 

Length

 

Width

 

range

mean

N

range

Mean

P4

7.12-7.92

7.65

7

8.76-9.53

9.19

M1

9.56-10.24

9.9

12

10.86-12.02

11.5

M2

10.06-10.98

10.5

15-13

11.81-13.16

12.6

M3

 

9.58

1

 

10.29

p4

 

6.77

1

 

6.45

m1

11.49-12.17

11.83

7

9.95-11.02

10.46

m2

10.71-12.71

11.56

16

10.29-11.83

11

m3

10.27-10.6

10.6

4

8.89-10.34

9.6

 

TABLE 2. Distribution of morphotypes for lower and upper cheek teeth of the Hayranlı Gliridae. The specimens that are separated according to morphotypes b and d of P4; B and C of M1/2; R of M3 in the upper dentition, and morphotypes b of p4; 1 and 2 of m1; 1 and 2 of m2; and 1B of m3 in the lower dentition are attributed to Myomimus maritsensis. The others (e of P4 and H of M1/2 in the upper dentition; 3 of m1 and 3 of m2 in the lower dentition) are attributed to Microdyromys koenigswaldi. Morphotype classification as cited in Daams (1981).

table 2

TABLE 3. Material and measurements of Microdyromys koenigswaldi from Hayranlı locality.

 

 

Length

 

Width

 

range

mean

N

range

mean

P4

 

7.99

1

 

9.47

M1-2

10.16-10.45

10.3

2

10.76-12.09

11.37

m1

9.74-10.04

9.89

2

8.89-10.27

10.27

m2

10.11-10.52

10.25

3

10.55-11.23

10.8

 

TABLE 4. Summary statistics of the variables for M. koenigswaldi and My. maritsensis from Hayranlı. Data for Hypnomys morpheus and Eliomys quercinus ophiusae imported from Hautier et al. (2009).

 

Tooth Facet

Species

Sample

N fs

N ws

N sp

N lp

m

SD

m

SD

m

SD

m

SD

Hypoconid

Myomimus maritsensis

10

34.8

11,21

5.1

3.31

30.3

7.63

11.6

3.17

Microdyromys koenigswaldi

2

34

0

4

2.83

37.5

10.61

4.5

0.71

Hypnomys morpheus

21

28.8

14,1

3.33

14.2

25.43

14

5.62

3.6

Eliomys quercinus ophiusae

8

6

3.2

2.75

11.6

15.5

9

3.87

1.89

 

TABLE 5. ANOVA performed on N fs, N ws, N sp, and N lp microwear variables.

 

ANOVA

Variables

MS

df

F

p

 

N fs

         
   

species

2067.91

2

14.35

0.0001

 

 

error

144.1

36

 

 

 

N ws

         
   

species

29.6

2

2.229

0.12

 

 

error

239.1

36

 

 

 

N sp

         
   

species

1387

2

8.852

0.0007

 

 

error

156.7

36

 

 

 

N lp

         
   

species

164.1

2

15.62

0.0001

 

 

error

10.51

36

 

 

 

 

 

FIGURE 1. 1: Active geodynamic map of eastern Mediterranean region and location of the study area (Kaymakçı et al., 2010). 2: Geologic map of the Sivas Basin simplified from 1/500.000 scale geological map sheet of Directorate of Mineral Research and Exploration, with location of the Hayranlı locality. 3: Stratigraphical column of the fossil bearing İncesu Formation and vertical distribution of the important localities. 4: Satellite image of the Hayranlı study area with location of the selected localities.

 figure 1

FIGURE 2. Nomenclature of parts of the Gliridae cheek teeth (after Daams, 1981 and Garcia-Paredes et al., 2010).

 figure 2

FIGURE 3. Upper and lower cheek teeth attributed to Myomimus maritsensis from Hayranlı. Upper dentition: 1-3 P4; 5-8 M1; 9-12 M2; 4 M3. Lower dentition: 13 p4; 14-19 m1; 20-24 m2 and 25, 26 m3. All the teeth are pictured at the same magnification and as if they were from the right side; figure letters are underlined for inverted teeth.

 figure 3

FIGURE 4. Upper and lower cheek teeth attributed to Microdyromys koenigswaldi from Hayranlı. Upper dentition: 1 P4; 2 and 3 M1/2. Lower dentition: 4 M1 and 5 M2. All the teeth are pictured at the same magnification and as if they were from the right side; figure letters are underlined for inverted teeth.

 figure 4

FIGURE 5. Spatial distribution of 1: Microdyromys; 2: Peridyromys; and 3: Myomimus genera from the Oligocene to the Pliocene (updated data from NOW database (Fortelius, 2013)).

 figure 5

FIGURE 6. 1: Position of the hypoconid on glirid's second lower molar; 2: SEM photomicrograph at 450x of the dental facet surface showing microwear patterns. SEM photomicrographs of the hypoconid of the second lower molar, 3: Myomimus maritsensis; 4: Microdyromys koenigswaldi.

 figure 6

FIGURE 7. Abundance of Gliridae species from the entire fossil and extant records (updated after Daams and De Bruijn, 1995; NOW Database (Fortelius, 2013) in the context of Cenozoic trends in average temperature and atmospheric CO2 (Strömberg, 2011; Royer, 2006). Relative temperature estimates during the last 40 Ma, Northern Hemisphere and Antarctic ice sheets (the dashed bar represents periods of minimal ice coverage and the full bar represents close to maximum ice coverage) ollows those of Zachos et al. (2001) and Strömberg (2011). The mean faunal hypsodonty index of all large herbivorous-omnivorous mammal taxa (from Greece-Afghanistan) follows Fortelius et al. (2002), Eronen et al. (2009, 2010a, b), and Strömberg (2011). The phylogenetic relationship of the Microdyromys is modified from Freudenthal and Martin-Suarez (2007a) and Daams (1981). Abbreviations: ELMA, European Land Mammals Age; Ma, million years; Plio., Pliocene; Plt., Pleistocene.

figure 7

 

 

Microwear data for Myomimus maritsensis (N:10) and Microdyromys koenigswaldi (N:2) from Hayranlı (N fs-number of fine scratches, N ws –wide scratches, N sp-small pits, N lp-large pits).

 

Specimen

Species

N fs

N ws

N sp

N lp

58-HAY/84-SM1

Myomimus maritsensis

31

1

32

13

58-HAY/84-SM2

Myomimus maritsensis

17

3

20

6

58-HAY/84-SM3

Myomimus maritsensis

28

5

33

6

58-HAY/84-SM4

Myomimus maritsensis

30

8

38

14

58-HAY/84-SM5

Myomimus maritsensis

37

9

46

12

58-HAY/84-SM6

Myomimus maritsensis

28

3

31

15

58-HAY/84-SM7

Myomimus maritsensis

43

9

52

12

58-HAY/84-SM8

Myomimus maritsensis

59

0

59

11

58-HAY/84-SM9

Myomimus maritsensis

35

8

43

14

58-HAY/84-SM10

Myomimus maritsensis

40

5

45

13

58-HAY/84-SM11

Microdyromys koenigswaldi

34

6

40

5

58-HAY/84-SM12

Microdyromys koenigswaldi

34

2

36

4

Dental microwear variables (N fs, N ws, N sp and N lp) for Hypnomys morpheus and Eliomys quercinus ophiusae imported from Hautier et al. (2009).

 

kayaFerhat Kaya
Department of Geosciences and Geography
University of Helsinki
PO Box 64 (Gustaf Hällströmin katu 2a)
00014 Helsinki
Finland
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Ferhat Kaya studied paleoanthropology at the University of Ankara, obtaining bachelor and master degrees, and for nearly fifteen years has participated in paleontological fieldwork under several research projects in Turkey and Africa. Currently, he is doing his PhD in mammal paleontology, with a focus on understanding African Neogene climatic controls and environmental processes via ecometrics, under the supervision of Mikael Fortelius at University of Helsinki, Finland. Throughout field experiences he has had a number of significant opportunities to learn firsthand about the evolution and dispersal of mammal species during the Neogene in Africa, Europe, and Asia. Further studies building on these encounters have deepened many questions in his mind about evolution, dispersal of Eurasian and African mammals, and their relation with climate change and other environmental forces.

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nuretdinNuretdin Kaymakçı
Department of Geological Engineering
Middle East Technical University
Ankara 06531
Turkey
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Nuretdin Kaymakçı is Professor of Geology at Middle East Technical University, Ankara, Turkey. He graduated from Middle East Technical University, and obtained his PhD in tectono-stratigraphy from the Faculty of GeoSciences (Vening Meinesz Research School of Geodynamics) at the Utrecht University, the Netherlands. He is author and co-author of various works on structural geology/tectonics, active tectonics, fault kinematics and paleostress inversion, seismic interpretation (2D&3D), basin analysis, application of paleomagnetism, and remote sensing and GIS.