Scontromeryx falcidens ( Mazza et Rustioni, 2011 )

Van Der Geer, Alexandra A. E., 2014, Systematic revision of the family Hoplitomerycidae Leinders, 1984 (Artiodactyla: Cervoidea), with the description of a new genus and four new species, Zootaxa 3847 (1), pp. 1-32 : 15-17

Scontromeryx falcidens ( Mazza et Rustioni, 2011)

Taxon A—Mazza & Rustioni 1999 (partim): p. 306 [SCT70, SCT103, 177].

Hoplitomeryx falcidens Mazza & Rustioni, 2011 — Mazza & Rustioni 2011 (partim): p. 1304, 1312, 1330, fig. 1, 2, 5, tables 1, 2 [SCT70, SCT82, SCT103, SCT177].

Holotype. Left hemimandible SCT177 ( Figure 1 , D, E, F, in Mazza & Rustioni 2011).

Paratypes. Maxillary SCT70, mandible fragments SCT103, SCT82.

Revised diagnosis. Small-sized, mesodont species. Lingual cusps tightly spaced in M2 and M3; metacone sometimes with small pillars on labial wall of upper molars; entostyle absent; mandible slender, with moderately sinuous horizontal ramus and convex ventral profile under cheek teeth corpus; paraconid absent or present only in unworn lower premolars; in p2 protoconid and metaconid of same height; p4 compressed mesiodistally, with enlarged and fairly complicated mesial trigonid and relatively small talonid; in lower molars labial cuspids triangular, widely spaced and somewhat backward-verging; metastylids and postentocristids well developed and protruding lingually in m1; postentocristid hardly developed in m3; ectostylid low and robust in m1, low and blunt in m3; hypoconulid and entoconulid with distal margins separated to halfway along the crown height; enamel smooth; weak cingulum at the base of the protoconid in m1.

Differential diagnosis. Differs from Scontromeryx minutus by having a mediodistally compressed lower p4 (L/W ratio 1.3 vs 1.5), lacking a paraconid in lower premolars, and having smooth enamel on labial side of cheek teeth.

Derivation of name. According to Mazza & Rustioni (2011), the species is characterized by sabre-like upper canines (falx, gen. falcis, Latin, sickle, scythe; dens, Latin, masculine, tooth). However, maxillary SCT177 lacks canines and the presence of a canine was based on material from the Gargano.

Preservation and deposition. Soprintendenza Archeologica dell’Abruzzo (Chieti, central Italy).

Type locality and horizon. Tortonian Scontrone Member of the Lithothamnium Limestone ( Patacca et al. 2008; 41°45'15.54''N, 14°02' 13.14''E), outskirts of Scontrone, southern border of the National Park of Abruzzi, L’Aquila, central Italy.

Description. See Mazza & Rustioni (2011). Additional characters shown by paratypes revised after Mazza & Rustioni (2011). SCT70 (M2-3) is a maxillary fragment, SCT82 (m3) and SCT103 (p2–m1) are mandible fragments. m3. The two mesial cuspids are not preserved (shown by SCT82). Hypoconid markedly triangular and very inclined backwards. Entoconid fairly swollen at base of crown but postentocristid barely developed. Low, blunt ectostylid. Hypoconulid and entoconulid both tear-shaped and about the same size. Distal margins of these two conulids keep separated until about halfway the height of the crown. M2–3. Small enamel pillars at the base of the metacone. Styles and ribs very strong. Metaconule with well-develop spur. Lingual cusps in tight contact with one another. No entostyle. M3 with large metaconule.

Measurements. See Table 2 .

Figures

FIGURE 1. Schematic map of present-day southern Italy showing the areas of Gargano and Scontrone with fossiliferous sites. Inset gives an overview of Italy and the position of the referred region. 1 = Poggio Imperiale, 2, San Nazario; 3, Apricena; 4, San Severo; 5, Foggia. The majority of fossiliferous fissure fillings is located between 1, 2 and 3. Foggia yielded no fossils but is the capital of the province Foggia. Bari is the capital of the region Apulia. Scontrone is a village in the region Abruzze, province L'Aquila. The Foggia Graben or Tavoliere delle Puglie (about sea-level) separates Gargano from the mountain ridges in the West and includes Foggia and San Severo.

Tables

TABLE 2. Dental measurements (L = length, W = width; in mm) of the mandibular (above) and maxillar fragments (below) from Scontrone, mandibular premolar / molar ratio and body mass estimation (BM in kg) based on lower molar row length after Damuth (1990) for selenodont browsers. * alveolar measurements. The specimens are sorted according to increasing size. Dental measurements from Mazza & Rustioni (2011, 1999, 1996).

Mandible fragments	species	Lp2–m3	Lm1–m3	Lm1 / Wm1 Lm2 / Wm2	Lm3 / Wm3	p/m ratio	BM
SCT88	S. apulicus	53.9	35	10.2 / 7 11.6 / 7.7	14.7 / 7.8	0.54*	18.2
SCT77	S. minutus	-	36.7	10.3 / 7 11.8 / 8	16.1 / 8	-	21.3
SCT76	S. apulicus	-	36.9	10.6 / - 11.3 / -	14.3 / -	-	21.7
SCT177	S. falcidens	56.8	38.4	10.1 / 8.2 8.3 / 7*	13.8 / 6.1*	0.48	24.8
SCT60	S. minutus	-	38.9	10.4 / 6.8 11.7 / 7.6	16.3 / 7.8	-
SCT155	S. minutus	58	39	10.2 / 6.4 11.9 / 8.2	17.2 / 8.6	0.48	26.2
SCT72	S. mazzai	-	-	- -	17.6 / 9.3	-
SCT50	S. apruthiensis	-	40.3	10.2 / - 12.5 / 7.7	18.1 / 7.8	-	29.2
SCT51	S. apruthiensis	-	-	10.9 / 8? -	-	-
SCT16	S. apruthiensis	-	41.5	11.5 / - 12 / -	18 / -	-	32.3
SCT81	S. apruthiensis	-	41.9	11.7 / 9.7 12.3 / 10.1	18.7 / 9.6	-	33.3
SCT102	S. apruthiensis	-	42.7	10.5 / 7.6 12.7 / 8.8	19.5 / 7.9	-	35.6
SCT29	S. apruthiensis	-	43.4	10.8 / 7.2 13.1 / 7.5	19 / 7.5	-	37.6
SCT71	S. apruthiensis	-	-	- -	19.6 / 8	-	-
SCT58+SC T67	S. apruthiensis	-	-	- 14.0 / 7.9	-	-	-
SCT89	S. apruthiensis	-	-	12.2 / 7.1 14.1 / 7.3	-	-	-
SCT20	S. magnus	-	47.8	15 / 9.6 15.5 / 9.7	20 / 10.1	-	52.1
SCT80	S. mazzai	-	-	- -	20.1	-
Maxilla fragments		LM1 / WM1	LM2 / WM2	LM3 / WM3
SCT70	S. falcidens	-	9.3 / 11.5	11.2 / 10
SCT59	S. apruthiensis	10.3 / 11.9	13 / 12	15.8 / -
SCT86	S. magnus	15.2 / 16.5	-	-
SCT18	S. magnus	16.1 / -	13.3 / -	-