Ratufa, Sciurus and Paramys

Paramys compressidens (Leidy 1871; Matthew 1910; middle Eocene, 45 mya) is one of the earliest known squirrel-like rodents, but others of its kind preceded the multituberculates, like Shenshou in the Late Jurassic. Manual digit 1 is absent. Compare to the extant Ratufa (above).

Ratufa indica (Erxleben 1777, extant, Indian giant squirrel, 36cm + 60cm tail) is an arboreal rodent and the largest living squirrel. Some species eat bird eggs and insects, but normal diet includes fruit, flowers, nuts and tree bark.

Sciurus vulgaris (Linneaus 1758; snout-vent length = 20cm + 20cm tail) is the extant red squirrel.

Glaucomys volans (Linneaus 1758; snout-vent length = 10cm +10cm tail) is the extant Southern flying squirrel convergent with basal flying multituberculates, like Vilevolodon. These are gliders, not flappers or fliers, as should be obvious.

Erxleben JCP 1777. Systema regni animalis per classes, ordines, genera, species, varietates cum synonymia et historia animalium. Classis I. Mammalia [Animal kingdom system by class, order, genus, species, varieties with synonyms and animals' history. Class I. Mammalia.] (in Latin). 42. Leipzig, Germany: Impensis Weygandianis.

Leidy J 1871. Remains of extinct mammals from Wyoming. Proceedings of the Academy of Natural Sciences 23: 113–116.

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

Matthew WD 1910. On the osteology and relationships of Paramys and the affinities of the Ischyromyidae. Bulletin of the American Museum of Natural History, 28:43–72.

wiki/Paramys
wiki/Ratufa
wiki/Sciurus
wiki/Glaucomys