DEVINOPHOCINAE, Koretsky & Holec, 2002

Koretsky, I. A. & Rahmat, S. J., 2021, Unique Short-Faced Miocene Seal Discovered In Grytsiv (Ukraine), Zoodiversity 55 (2), pp. 143-154 : 150-151

Subfamily DEVINOPHOCINAE

Only the fossil sister taxa Devinophoca emryi and D. claytoni (early Mid-Miocene, Badenian, 16.3–12.8 Ma) are described within this subfamily. Planopusa semenovi differs from these taxa by: alveoli of upper incisors forming a straight line; pre-orbital part of the maxilla has very short concavity over P1 and convexity starting over P2; much smaller total size.

There are no described fossil cystophorine seal skulls to date. Described fossil monachine skulls have a different dental formula and are much younger in geological age; in addition, their skulls were much larger with a reverse ratio between M1 and P4.

Cladistic analysis

The data matrix for the 14 included characters is shown in table 3. Cranial, mandibular and dental characters and character-states for Phocidae : 0, designates the most primitive state among the studied taxa; 1–2, derived states;?, unknown or missing data. Some characters have the opposite polarity to that of Berta and Wyss (1994) and Burns and Fay (1970), while other characters have the same polarity as that of Chapskii (1974). Some characters were updated and modified from Koretsky (2001), Koretsky and Grigorescu (2002), and Koretsky and Rahmat (2015).

The analysis was performed with NONA after Goloboff (1999) and Winclada from Nixon (1999) using a heuristic search of the phocid taxa of 14 unweighted characters. The resulting single Wagner most parsimonious tree generated by Winclada with 184 steps long, having Consistency Index of 0.75, and Retention Index 0.81.

The matrix of character-state data for 19 species of fossil and modern phocids is given in Table 3; in addition, the following taxa were used as outgroups: fossil representatives, such as Allodesmus and Puijila , and the recent mustelid Lontra .

Skull

1. Anterior palatine foramina: (0) round and deep; (1) oval and shallow; (2) indistinctively marked ( Burns and Fay, 1970).

2. Palatal groove: (0) present; (1) absent.

3. Palatal process of maxillary bone: (0) flat; (1) convex.

4. Rostrum: (0) short, relative to skull; (1) elongated ( Chapskii, 1974:299).

Teeth

5. Number of incisors: (0) 3/2; (1) 2/2; (2) 2/1 ( Chapskii, 1974:289; in contrast to Burns and Fay 1970:380); (3) 3/1.

6. Roots of postcanine teeth (P2/p2 – P3/p3): (0) one (fused); (1) two ( Berta and Wyss, 1994:51).

7. Roots of P4/p4: (0) three; (1) two; (2) one.

8. Crowns of postcanine teeth: (0) multicusped; (1) single-cusped.

9. Dimensions of postcanine teeth relative to longitudinal diameter of alveolus of upper canine: (0) more than 60.0 %; (1) less than 60.0 % or sub-equal.

10. Basal cingulum of postcanine teeth: (0) well developed; (1) not developed.

11. Number of additional cusps of premolars: (0) more than two; (1) no additional cusps.

12. Premolar: (0) aligned parallel to axis of tooth-row; (1) seated obliquely.

13. Upper incisors: (0) arranged in a curved arcade; (1) arranged in a straight line.

14. Second and third upper incisors: (0) third larger than second; (1) second larger than third, (2) all upper incisors equal in size.

Nodes of the present tree ( fig. 5 ) correspond to traditionally recognised phocid taxa. Only one new name is introduced here: inclusion of Devinophoca emryi within the subfamily Devinophocinae requires recognition of the new species.

The nodes on the cladogram shown in fig. 5 are supported by the following character transformations:

Node 1 (family Phocidae ): 8(0). This paraphyletic group with an ancestral or primitive character (multicusped crowns of postcanine teeth) is treated as plesiomorphic for the family.

Node 2 (subfamily Devinophocinae , possibly paraphyletic): 1(0); 5(3); 7(0). The anterior palatal foramina are round and deep; number of incisors. Paraphyly of D. claytoni : three fused roots of the postcanine teeth.

Node 3 (subfamily Phocinae ): 9(0,1); 5(0). The diameter of the infraorbital foramen is equal to or greater than the diameter of the maxillary canine alveolus; the length of auditory bulla is less than the distance between them. In addition, character 9(1) shows homoplasy in Neomonachus schauinslandi and Leptophoca lenis .

Node 4 (subfamily Monachinae ): 2(1); 3(1); 13(0,1). The relative dimensions of the frontal and maxillary parts of nasals; shape of the anterior palatine foramina; maxilla forms a long concavity; reduced number of incisors.

Node 5 (subfamily Cystophorinae ): 5(2); 11(1); 14(1). The mastoid convexity directed sharply downward behind the mastoid process. Maxilla forms a short concavity; advance reduced number of incisors; no additional cusps on premolars. The second incisor is larger than the third one.

Figures

Fig. 5. The single, most parsimonious Wagner tree generated by Winclada with 184 steps long, having Consistency Index of 0.75, and Retention Index 0.81.