Kopidodon macrognathus (originally Cryptopithecus macrognathus Wittich 1902; Weitzel 1933/4; Tobien 1969; Naturmuseum Senckenberg; 115cm total length; middle Eocene, 47 mya) is traditionally considered, "a squirrel-like mammal with large canines." Here it nests basal to carnivores alongside Nasua, the coatimundi. The Messel fossil shows it had long hair and a bushy tail. There were 26-29 presacral vertebrae + 3 sacrals. The foreclaws were taller than wide (similar to arboreal mammals) and larger than the hind claws. The feet were plantigrade. The limbs were heavily muscled and designed for slow movement. The tail vertebrae diminished posteriorly to tiny elongate bones. Stomach contents include fruit and seeds.

Hapalodectes hetangensis  (Ting and Li 1987; 4.5cm skull length; Paleocene, 55 mya; IVPP V 5235) This skull was originally considered a mesonychid, but here nests with the marsupial clade leading to sabertooth taxa with a shrinking premaxilla. Note the encircled orbits rotated anteriorly as in Thylacosmilus, convergent with primates.

Paroodectes feisti (Springhorn 1980, Middle Eocene) was described as a miacid member. Here it is a relative of the ringtail, Bassariscus and the olingo, Bassaricyon at the base of the Carnivora.

Gustafsonia cognitus (Tomiya and Tseng 2016) formerly Miacis cognitus (Gustafson 1986, Middle Eocene to Early Oligocene). Anterior post-canine teeth were decreasing in size and number. The molars and canines were small. Close to Hapalodectes IVPP V5235 and Paroodectes at the base of the 'marsupial sabertooth' clade. The zygomatic is restored here based on elements now adhering to the mid-ventral skull.

Protictis haydenianus (formerly Didymictis Cope 1882, Middle Paleocene ~60 mya, ~75 cm in length, is known from a partial skull. Close to Hapalodectes. The postfrontal is crushed into the cranium. The naris is narrow in this clade.

Clemens WA and von Koenigswald W 1993. A new skeleton of Kopidodon macrognathus from the Middle Eocene of Messel and the relationship of paroxyclaenids and pantolestids based on postcranial evidence. Kaupia 3, 1993, S. 57–73.

Cope ED 1882a. Contributions to the history of the Vertebrata of the lower Eocene of Wyoming and New Mexico, made during 1881. Proceedings of the American Philosophical Society: 139-197.

Cope ED 1882e. Note on Eocene Mammalia. American Naturalist 16:522.

Springhorn R 1980. Paroodectes feisti, der erste Miacide (Carnivora, Mammalia) aus dem Mittel-Eozän von Messel. Paläontologische Zeitschrift (in German and Latin). 54 (1/2): 171–198.

Tobien H 1969. Kopidodon (Condylarthra, Mammalia) aus dem Mitteleozän (Lutetium) von Messel bei Darmstadt (Hessen). Notizblätter der hessischen Landesanstalt für Bodenforschung 97, 1969, S. 7–37.

Ting S and Li C 1987. The skull of Hapalodectes (?Acreodi, Mammalia), with notes on some Chinese Paleocene mesonychids. Vertebrata PalAsiatica. 25: 161–186.

Tomiya S and Tseng JT 2016. Whence the beardogs? Reappraisal of the Middle to Late Eocene Miacis from Texas, USA, and the origin of Amphicyonidae (Mammalia, Carnivora). Royal Society Open Science. 3 (10): 160518.

Weitzel K 1933. Kopidodon macrognathus Wittich, ein Raubtier aus dem Mitteleozän von Messel. Notizblätter des Vereins für Erdkunde der hessischen geologischen Landesanstalt Darmstadt 14, 1933, S. 81–88

wiki/Gustafsonia
wiki/Paroodectes
wiki/Ringtail
wiki/Hapalodectes
wiki/Protictius
wiki/Kopidodon