Capreolus constantini Vislobokova, Dmitrieva, and Kalmykov, 1995

Jiménez-Hidalgo, Eduardo & Bravo-Cuevas, Victor, 2015, A roe deer from the Pliocene of Hidalgo, central Mexico, Acta Palaeontologica Polonica 60 (4), pp. 807-813 : 808-810

Capreolus constantini Vislobokova, Dmitrieva, and Kalmykov, 1995

Figs. 3, 5 , 6 , Tables 1, 2.

Referred material.— Partial skeleton consisting of UAHMP 481, left mandible fragment with roots of p2, p3–m 2 in situ,

JIMÉNEZ-HIDALGO AND BRAVO-CUEVAS—PLIOCENE ROE DEER FROM MEXICO 809

A1 30 mm A 2 A 3 A 4 B 10 mm

and m3 alveolus; UAHMP 484 and UAHMP 485, humeri; UAHMP 490, olecranon process of ulna; UAHMP 486, left tibia; UAHMP 488, metacarpal; UAHMP 433, proximal fragment of metatarsal; UAHMP 487, left patella; and UAHMP 489, first right phalanx of digit IV of forelimb. UAHMP 432, p3; UAHMP 434, fragment of m3. All from Santa María Amajac, Hidalgo, Mexico; Pliocene.

Description. —The mandible is shallow dorsoventrally and little convex ventrally, but slightly increases in depth towards m3 ( Fig. 3). Its depth is 21.30 mm below p2, 23.60 mm below p4–m1, and 28.70 mm posterior to m3. The diastema is long (35.0 mm), and its dorsal border is acute. The teeth are brachyodont, and combine to a total anteroposterior length (p2–m3) of 95 mm. The p2 has two roots. The p3 has a strong and narrow anterior stylid, and bears a narrow anterior conid which is separated from the mesolingual conid by a deep anterior valley ( Figs. 3, 4A, B ). In the slightly worn specimen UAHMP 432, the mesolingual conid has an anterolingual and a posterolingual cristid, while in the moderately worn p3 of UAHMP 481, these cristids have disappeared. The back valley is closed owing to the fusion of the posterior cristid and the posterior stylid ( Figs. 3, 4A, B ), which in turn is connected to the posterolabial conid via a cristid.

The p4 is molariform, and the largest of the premolars ( Figs. 3, 4A ). Its anterior stylid is well developed. The anterior conid is connected to the mesolingual conid via the anteriorly elongated anterolingual cristid, which closes the narrow anterior valley ( Figs. 3, 4A ). The posterior valley is reduced to a small notch owing to the posterior elongation of the posterolingual cristid. The anterior and posterior valleys are connected, creating an oblique, long, and narrow valley ( Figs. 3, 4A ). The posterior cristid and the posterior stylid are very close, almost blocking the back valley. The mesolabial conid is separated from the posterolingual conid by a V-shaped notch. The transverse cristid is confluent with the mesolabial conid, but not with the mesolingual conid; instead, it forms a posterolingually directed projection that touches the posterolingual cristid ( Figs. 3, 4A ).

The mesostylid and entostylid of m1 are weakly developed, but the metastylid is well developed. The only preserved m2 is broken. On m3, the posterior fossetid and the back fossetid are united, and the entoconulid is poorly developed.

The humerus is robust ( Fig. 5A ) and bears a well-developed head, with the tuberosities being separated by a deep fossa. The distal trochlear surface extends somewhat into the olecranon fossa. Only the olecranon process of the ulna is preserved, and has a length of 38.06 mm and a width of 14.35 mm. The tibia is large and straight ( Fig. 5B ), bearing a well-developed tuberosity, U-shaped sulcus muscularis, and a prominent popliteal scar. The cnemial crest occupies about 1/3 of the total length of the preserved specimen, smoothly finishing toward its distal end. The patella has a triangular outline, with a width of 33.7 mm and an anteroposterior length of 20.11 mm.

The preserved metacarpal is robust, and shows a wide palmar sulcus, large distal foramina in the diaphysis, and a fused intertrochear notch ( Fig. 6A ). The proximal fragment of the metatarsal has a squared outline, with a transverse width of 23.72 mm and a proximodistal length of 20.29 mm. The first right phalanx is straight ( Fig. 6B ). Its proximal articular facets are high and dorsoventrally concave, with a deep and wide sulcus. The lateral facet is dorsoventrally shorter than the medial one, indicating that the phalanx likely belonged to digit IV ( Morejohn and Dailey 2004). The distal articular surface is relatively wide. The phalanx has a proximodistal length of 43.12 mm, and a transverse width of 16.38 mm and 13.27 mm across the proximal articular surface and the distal trochlea, respectively.

Geographic and stratigraphic range. —Late Pliocene (MN16) of Udunga, Western Trans-Vaikal, Russia; and Pliocene (Blancan?III) of Santa María Amajac, Hidalgo, Mexico.

Figures

Fig.5. Humerus and tibia of the cervid mammal Capreolus constantini Vislobokova, Dmitrieva, and Kalmykov, 1995 from the Pliocene of Hidalgo, Mexico. A. UAHMP 432, right humerus, in lateral (A 1), anterior (A2), and medial (A3) views. B. UAHMP 436, left tibia, in anterior (B1) and lateral (B2) views.

Fig. 6. Metacarpal and first phalanx of the cervid mammal Capreolus constantini Vislobokova, Dmitrieva, and Kalmykov, 1995 from the Pliocene of Hidalgo, Mexico. A. UAHMP 488, metacarpal, in anterior (A 1) and posterior (A 2) views. B. UAHMP 489, first phalanx, in anterior (B 1) and medial (B 2) views.

Fig. 4. Comparison of occlusal views of p3–m1 of the cervid mammal Capreolus constantini from the Pliocene of Hidalgo, Mexico, with selected extant cervids. A, B. Capreolus constantini. A. UAHMP 481. B. UAHMP 432, isolated p3. C. Capreolus capreolus, IPHES O-241. D, E. Odocoileus virginianus. D. INAH 16897, slightly worn. E. INAH 663, moderately worn. F. Navahoceros fricki, INAH 1082 (reversed), heavily worn. G. Cervus canadensis, INAH 1227 (reversed), moderately worn. H. Hippocamelus bisulcus, MLP 1364 (reversed), slightly worn.