Patriarchus rectus Ameghino, 1891

Fernández, Mercedes, Fernicola, Juan Carlos, Cerdeño, Esperanza & Reguero, Marcelo A., 2018, Identification of type materials of the species of Protypotherium Ameghino, 1885 and Patriarchus Ameghino, 1889 (Notoungulata: Interatheriidae) erected by Florentino Ameghino, Zootaxa 4387 (3), pp. 473-498 : 491

Patriarchus rectus Ameghino, 1891

Holotype. MACN-A 4005 ( Fig. 3 N ), right maxilla with alveolus of C and series P1–M3; MACN-A 4006 ( Fig. 3 O ), left maxillary fragment with series M1–3; and MACN-A 4007 ( Fig. 3 P ), mandibular fragment with incomplete symphysis, broken alveoli of left and right i1-2 and complete left series i3 –m3, all of them of the same individual.

Diagnosis ( Ameghino 1891: 293). “ De tamaño una mitad menor que las especies precedentes [ Patriarchus furculosus y Patriarchus distortus ] y de series dentarias superiores casi rectas, P3 a M2 mucho más prolongados en el lado interno. Incisivos intermedios inferiores más aplastados de arriba abajo. Longitud de la serie dentaria inferior, 43 milímetros. Ancho interorbitario de los frontales, 24 milímetros ”.

English translation. One half smaller than the preceding species [ Patriarchus furculosus and Patriarchus distortus ], with upper tooth rows almost straight, P3 to M2 much longer on the internal side. Lower median incisors more flattened. Length of the lower tooth row, 43 mm. Interorbital width of the frontals, 24 mm.

Comments. Ameghino (1891) erected this species but did not illustrate any specimens of it. According to Ameghino’s catalogue and to Mones (1986), the maxillary fragments MACN-A 4005 and MACN-A 4006, and the fragmented mandible MACN-A 4007, all of the same individual, are the type materials of this species. These specimens match the original diagnosis as they are smaller (length of P1–M3 = 30.5 mm; length of P2–M3 = 27.5 mm; length of p2–m3 = 29.23 mm) than the type material of Pa. furculosus (length of P2–M3 = 36.5 mm; length of p2–m3 = 41.05 mm) and Pa. distortus (length of P1–M3 = 37.3 mm), and the incomplete palate (MACN-A 4005 plus MACN-A 4006) exhibits almost straight upper tooth rows. It is noteworthy that there is no evidence of the frontals in MACN-A 4005 and MACN-A 4006, so it was not possible to measure the interorbital width of these elements. Additionally, the length occupied by the left lower tooth row (~ 41 mm) of MACN-A 4007 differs from the value provided by Ameghino (1891), but this is due to the breakage of the mandibular incisor area. Nevertheless, MACN-A 4005 to MACN-A 4007 are confirmed as the holotype of Pa. rectus .

Chronological and geographical distribution of the type specimen. Santacrucian SALMA, Santa Cruz Province.

Figures

FIGURE 3. Patriarchus palmidens, holotype MACN-A 9651a, mandibular symphysis with right i1–p1 and left i1–2 and the alveolus of i3, in labial (A), occlusal (B) and antero-labial (C) views; reproductions of figures 2 (D), 2a (E) and 2b (F) from Ameghino (1889, plate 15). Patriarchus furculosus, syntype MACN-A 3970, left maxillary fragment with P2–M3, in occlusal view (G); syntype MACN-A 3972, right mandibular fragment with p2–m3, in occlusal view (H); syntype MACN-A 3977, incomplete skull, dorsal view (I). Patriarchus distortus, holotype MACN-A 9634 to MACN-A 9638: MACN-A 9634, skull, ventral (J)and dorsal (K) views; MACN-A 9636, proximal epiphysis of right femur, in anterior view (L); MACN-A 9637 and MACN-A9638, proximal epiphyses of right tibia and fibula,articulated with the distal epiphysis of right femur, in lateral view (M). Patriarchus rectus, holotype MACN-A 4005, right maxillary fragment (vertically rotated) with alveolus of C and series P1–M3, in occlusal view (N); holotype MACN-A 4006, left maxillary fragment (vertically rotated) with M1–3, in occlusal view (O); holotype MACN-A 4007, mandibular fragment with incomplete symphysis, broken alveoli of left and right i1-2 and complete left i3–m3 series, in occlusal view (P). Patriarchus diastematus, holotypeMACN-A 4044, two maxillae with alveoli of C–P1 andright P2–M3 andleft P2–M2, in occlusal view (Q). Scale bar = 10 mm.