Palaeosinopa veterrima (Matthew 1901, Gingerich 1980; Rose and von Koenigswald 2005; Late Paleocene, 56-48 mya; YPM VP 027216) was originally considered a pantolestid insectivore, but here nests with Gobiohyus and the water opossum, Chironectes. It has been known as an amphibious piscivore and perhaps mollusc eater as the molars of older specimens tend to be worn flat. Palaeosinopa has a long, robust tail with chevrons. Manual digit 2 is longer than the others. Pedal digit 3 is longer. The femur is short and robust.

Sinopa rapax (Leidy 1871; Eocene-Early Oligocene; 50mya) was traditionally considered a creodont relative of Hyaenodon, but here nests between Dasyurus and Sarcophilus. It is slightly larger than Sarcophilus. Not sure about those premaxillary teeth. The dentary canines are larger than the maxillary canines. This genus is not related to Palaeosinopa.

Sinopa grangeri (Matthew 1906, NMNH = Smithsonian 5341) represented by a nearly complere skeleton, lacking manus and pes.

Limnocyon verus (Marsh 1872, Middle Eocene) is known from a complete skull and mandibles plus a few uncrushed post-cranial bones.

Thinocyon medius (Marsh 1872, Matthew 1909, Morlo and Gunnell 2003, Middle Eocene) was traditionally considered a small limnocyonine hyaenodontid mammal, but here nests with Vincelestes among the creodont marsupials. According to Morlo and Gunnell: "Limnocyoninae are relatively small hyaenodontid creodonts characterized by reduction and loss of upper and lower third molars."

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

Marsh OC 1872. Preliminary description of new Tertiary mammals. American Journal of Science and Art, 4: Part I: 122-128, Part 11-IV: 202-224.

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

Matthew WD 1906. The Osteology of Sinopa, a Creodont Mammal of the Middle Eocene. Proc. U. S. Nat. Mus., 30:203-233, pl. XVI, and text figs. 1-20.

Matthew WD 1909. The Carnivora and Insectivora of the Bridger Basin, middle Eocene. Memoires of the American Museum of Natural History, 9: 289-567.

Morlo M and Gunnell GF 2003. Small limnocyonines (Hyaenodontidae, Mammalia) from the Bridgerian Middle Eocene of Wyoming: Thinocyon, Prolimnocyon, and Iridodon, new genus. Contributions from the Museum of Paleontology, The University of Michigan31(2):43–78.

Rougier GW, Wible JR and Hopson JA 1992. Reconstruction of the cranial vessels in the Early Cretaceous mammal Vincelestes neuquenianus: implications for the evolution of the mammalian cranial vascular system. Journal of Vertebrate Paleontology 2:188–216. https://doi.org/10.1080/02724634.1992.10011449

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