Deinogalerix sp.

Savorelli, Andrea, Masini, Federico, Mazza, Paul P. A., Rossi, Maria Adelaide & Agostini, Silvano, 2017, New species of Deinogalerix (Mammalia, Eulipotyphla) from the late Miocene of Scontrone (Abruzzo, central Italy), Palaeontologia Electronica 11 (2), pp. 1-26 : 16-18

Deinogalerix sp.

Figure 9

Material. Left hemimandible SCT 243.

Type Locality. Outskirts of Scontrone , southern border of the National Park of Abruzzi, L’Aquila, central Italy (41°45′15.54″N, 14°2′13.14″E) .

Horizon. Scontrone Member, Lithothamnion Limestone.

Age. Lower Tortonian (lower upper Miocene) ( Patacca et al., 2008b).

Measurements. See Table 2.

Description Specimen SCT 243 ( Figure 9.1-2 ). Still partly embedded in rock. Specimen broken in front of mesial root of p3 and at level of m2. p3, basal parts of p4 and m1, and mesial part of m2 still preserved. Part of both roots of p2 visible. p2 presumably somewhat smaller than p3 based on relative proportion of the roots. Specimen cut by fracture between p3 and p4 that displaces rostral portion of horizontal ramus ventrally. Mental foramen under mesial border of distal root of p3 and elongated mesially by groove. Horizontal ramus quite high and thick under molar section and tapering rostrally.

p3. Slightly worn, blunt, fairly low-crowned, dominated by protoconid triangular and symmetrical in side view. Metaconid absent. Labially, protoconid with relatively swollen base. Two roots straight and divergent mesio-distally from one another. In occlusal view crown slender mesio-distally with subtriangular outline and talonid extended distally and with blunt and small cuspule, prominent disto-lingually. p3 narrower and markedly smaller than p4 ( Table 2) and separated from alveoli of p2 by short diastema.

p4. Crown badly damaged, only lingual and mesiolabial part of enamel wall preserved. Tooth large and massive, much more than p3. Occlusal outline sub-triangular, slightly wider distally, distal margin of tooth straight but obliquely inclined disto-labially. m1. General outline of crown and mesio-labial part of cingulum preserved. m1 largest tooth (approximately same length as p4) with very elongated trigonid. Mesial part of lingual enamel wall between paraconid and metaconid, i.e., postparacristid, slightly concave lingually and with no mesiolingual bulge.

m2. Undescribable fragment.

Comparison. SCT 243 shares with Deinogalerix samniticus sp. nov. the relative proportions of p3, p4, and m1. It differs from it by its smaller overall size, and by having a rostrally tapering horizontal ramus. p3 is more slender and not roundish as in D. samniticus sp. nov., and p4 has an oblique and not transverse distal edge. The trigonid of m1 is uniformly concave lingually without any trace of mesiolingual bulge.

SCT 243 has p3 as large as that of D. masinii , p4 the same size as that of D. brevirostris , and m1 slightly larger than that of D. freudenthali ( Figure 7 ).

Figures

FIGURE 7. Comparisons of p3–m3 lengths in the different species of Deinogalerix, as well as in Parasorex, Galerix, Schizogalerix, and Apulogalerix (measurements and abbreviations in Table 3). 1, The graph shows that in Apulogalerix, Parasorex and other continental galericines molars grow progressively larger towards m1, which is the largest tooth of the row. The fourth lower premolar is larger than p3, which, in contrast, is the smallest of the toothrow (it is somewhat smaller than m3). Compared to the mainland counterparts, Deinogalerix bears a very large m1 (due to the increase of the trigonid length) and larger premolars, that grow progressively smaller moving rostrally, but less than in the continental genera (p3 intermediate in size between m1 and m2). The Scontrone specimen shows the size increase from m3 to m1 typical of Deinogalerix. In contrast, it bears a very large p4, similar in size to m1 and in the dimensional ranges of D. koenigswaldi, and a very reduced p3, more similar to those of the smaller and more primitive species of Deinogalerix from Gargano. 2, Ratio diagram comparing the p3–m3 lengths (see Table 4) in Deinogalerix samniticus sp. nov. with other species of Deinogalerix, using Parasorex socialis from La Grive as the standard (horizontal line). All the Deinogalerix specimens show a similar trend where the proportions of m2 and m3 are parallel to the standard, whereas, starting from m1, the teeth proportionally increase in size respect to the standard. It is noteworthy that this trend reaches its maximum expression in D. koenigswaldi. Compared to the other species of Deinogalerix, the curve of D. samniticus sp. nov., shows a steeper rise toward p4, and it is the only one that drops toward p3.

FIGURE 9. Left mandible (SCT 243), Deinogalerix sp. 1, lateral view; 2, dorsal view.