Palaeosinopa and Phoca

Palaeosinopa veterrima (Matthew 1901, Rose and von Koenigswald 2005; Late Paleocene, 56-48 mya; YPM VP 027216) was originally considered a pantolestid insectivore, but here nests with the seal, Phoca. It has been known as an amphibious piscivore and perhaps mollusc eater as the molars of older specimens tend to be worn flat. Unlike seals, Palaeosinopa has a long, robust tail. Like seals, the medial manual and pedal digits, especially digit 2 are longer than the others. The femur is short and robust. The scapulae are similar in shape.

Phoca vitulina (the harbor or common seal, Linneaus 1758, up to 1.8 m in length, Pliocene, 10 mya to present) has trasnformed its limbs into flippers. It is a swimming piscivore derived from Procyon and a sister to Canis.

Gingerich PD 1980. A New Species of Palaeosinopa (Insectivora: Pantolestidae) from the Late Paleocene of Western North America. Journal of Mammalogy 61 (3): 449.

Linnaeus C von 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.

Matthew WD 1901. Additional observations on the Creodonta: Bulletin of the
American Museum of Natural History, v. 14, p. 1–38.

Rose KD and von Koenigswald W 2005. An exceptionally complete skeleton of Palaeosinopa (Mammalia, Cimolesta, Pantolestidae) from the Green River Formation, and other postcranial elements of the Pantolestidae from the Eocene of Wyoming (USA): Palaeontographica Abteilung A 273: 55–96.

wiki/Palaeosinopa
wiki/Phoca

Mammalia

Ornithorhynchus and kin

Marsupials - Metatheria

Eomaia and kin

Placentals - Eutheria

Carnivora