TABLE 1. Selected measurements for type specimen (LACM/CIT 1854) of Protitanops curryi, a stratigraphically associated and possibly conspecific specimen (LACM/CIT 2007), and summary statistics for Protitanops curryi material from West Texas and Mexico combined. Abbreviations: N - number of specimens; SD - standard deviation; Min - minimum observation; Max - maximum observation; CV - coefficient of variation.
| Titus Canyon | West Texas specimens combined | |||||||
| LACM /CIT 1854 |
LACM /CIT 2007 |
N | Mean | SD | Min | Max | CV | |
| ventral skull length | 688 | 4 | 663 | 25 | 642 | 698 | 4 | |
| proximodistal horn length | 134 | 2 | 110 | 42 | 80 | 140 | 39 | |
| horn circumference at proximal base | 277 | 5 | 248 | 34 | 220 | 300 | 14 | |
| thickness of zygomatic arch | 88 | 6 | 82 | 22 | 40 | 98 | 26 | |
| upper canine crown width | 23 | 3 | 26 | 3 | 24 | 30 | 11 | |
| P3 mesiodistal length | 29 | 37 | 8 | 33 | 3 | 30 | 37 | 9 |
| P3 labiolinugal width | 38 | 46 | 8 | 41 | 3 | 35 | 45 | 8 |
| M2 mesiodistal length | 65 | 83 | 6 | 72 | 4 | 68 | 79 | 6 |
| M2 labiolingual width | 64 | 69 | 6 | 69 | 5 | 60 | 72 | 7 |
| P2-P4 mesiodistal length | 84 | 6 | 100 | 6 | 91 | 104 | 6 | |
| M1-M3 mesiodistal length | 182 | 5 | 195 | 19 | 180 | 225 | 10 | |
| lower canine crown width | 3 | 28 | 8 | 19 | 36 | 30 | ||
| p3 mesiodistal length | 2 | 30 | 3 | 28 | 32 | 10 | ||
| p3 labiolingal width | 2 | 22 | 2 | 20 | 23 | 10 | ||
| m2 labiolingual length | 4 | 38 | 3 | 33 | 40 | 9 | ||
| m2 mesiodistal length | 57 | 4 | 63 | 4 | 58 | 68 | 6 | |
| p2-p4 mesiodistal length | 3 | 90 | 2 | 89 | 92 | 2 | ||
| m1-m3 mesiodistal length | 190 | 3 | 220 | 20 | 200 | 240 | 9 | |
TABLE 2. Character attribute differences of species of Brontotheriita. Shaded cells indicate character differences when compared to specimens referred to Protitanops curryi from the Chambers Tuff, Chisos and Prietos Formations.
| Character | Character number | Chambers Tuff (Pc) | Chisos Fm. (Pc) | Prietos Formation (Pc) | Devil's Graveyard Fm. (cf. Po) |
Protitanops curryi | Eubrontotherium clarnoensis | Notiotitanops mississippiensis | Parabrontops gobiensis | Duchesneodus uintensis | Dianotitan lunanensis | Parvicornus occidentalis | Megacerops coloradensis | Megacerops kuwagatarhinus |
| frontonasal horns elongate | 3 | n | n | ? | ? | n | n | n | n | n | n | n | y | y |
| nasal incision extends posterior to P3 | 6 | y | y | ? | ? | y | y | n | y | y | y | y | n | n |
| anterior rim of orbit anterior to molars | 13 | n | n | n | ? | n | n | y | n | n | n | n | y | y |
| large cranial dome present | 21 | n | n | ? | ? | n | n | ? | n | y | n | n | n | n |
| lateral swelling on zygomatic arch | 26 | y | y | y | ? | y | n | ? | n | y | y | n | y | y |
| anterior margin of posterior nares roughly between M3 protocones | 28 | n | n | n | n | y | n | y | y | n | n | n | y | n |
| emargination of posterior nares lacking | 29 | n | n | n | n | n | n | n | n | y | y | n | y | y |
| Paired ventral sphenoidal fossae present | 31 | n | n | n | ? | n | n | n | n | n | n | n | n | y |
| thick nuchal crest | 39 | n | n | ? | ? | n | n | ? | n | n | y | n | y | n |
| massive occipital pillars | 40 | n | n | ? | ? | n | n | ? | n | n | n | n | y | y |
| # upper incisors | 42 | ? | 2 | ? | 2 | 2 | 2 | 2 | 3 | 2 | 2 | 2 | 2 | ? |
| globular upper incisors | 44 | ? | y | ? | n | y | y | y | y | y | y | n | y | ? |
| incisor row arched | 45 | n | n | ? | y | n | n | n | n | n | n | y | n | ? |
| upper postcanine diastema | 46 | y | y | ? | y | y | y | y | y | n | n | y | n | n |
| P2 preprotocrista strong | 51 | ? | y | y | y | y | y | y | n | y | y | y | y | y |
| molar metaloph present | 67 | n | n | n | n | n | n | n | n | n | n | n | n | y |
| M3 hypocone present | 69 | y | y | y | y | y | y/n | y | y | y | y | y/n | y | y |
| mandibular symphysis posterior to P4 trigonid | 71 | y | ? | ? | n | y | y | y | ? | y | ? | n | y | ? |
| # lower incisors | 72 | 3 | ? | ? | ? | ? | 3 | ? | ? | 3 | ? | 3 | 2 | ? |
| mandibular postcanine diastema | 76 | y | ? | ? | ? | y | y | ? | ? | y | ? | y | n | ? |
| p3 metaconid present | 82 | ? | ? | ? | ? | ? | n | y | ? | y | ? | y/n | y | ? |
| horn broadest in antero-posterior direction | 90 | y | y | ? | ? | y | y/n | ? | y | y/n | y/n | y | n | n |
| antero-lingual upper premolar cusp present | 93 | n | n | n | n | n | n | n | n | y | n | n | y/n | y/n |
| bifurcated horns | - | n | n | ? | ? | n | n | n | n | n | n | n | n | y |
