''Agilodocodon'' was a genus of

shrew Shrews ( family Soricidae) are small mole-like mammals classified in the order Eulipotyphla. True shrews are not to be confused with treeshrews, otter shrews, elephant shrews, West Indies shrews, or marsupial shrews, which belong to dif ...

-sized

docodont Docodonta is an Order (biology), order of extinct Mesozoic Mammaliaformes, mammaliaforms (advanced cynodonts closely related to true Crown group, crown-group mammals). They were among the most common mammaliaforms of their time, persisting from t ...

from the

Middle Jurassic The Middle Jurassic is the second Epoch (geology), epoch of the Jurassic Period (geology), Period. It lasted from about 174.1 to 161.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relativel ...

, believed to be the earliest known tree-climbing

mammaliaform Mammaliaformes ("mammalian forms") is a clade of synapsid tetrapods that includes the crown group mammals and their closest extinct relatives; the group radiated from earlier probainognathian cynodonts during the Late Triassic. It is defined a ...

. It contains one species, ''A. scansorius''.

Appearance

''Agilodocodon'' measured approximately from head to tail, weighing about 27 grams. Its appearance was similar to a squirrel, with a long snout, curved, horny claws and flexible ankle and wrist joints typical of modern arboreal mammals. The front teeth were spade-like, indicating that ''Agilodocodon'' could gnaw tree bark and consume gum or sap. Evolutionary biologist Frietson Galis, however, questioned whether ''Agilodocodon'' gnawed bark and ate tree sap, saying its teeth "are quite different" from the modern sap-eating primates, and the long, thin lower jaw seems too weak for chomping on tree bark.

Discovery

The fossil of ''Agilodocodon scansorius'',

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

BMNH 001138, along with that of '' Docofossor brachydactylus'', was originally found by farmers in the Chinese

Tiaojishan Formation The Tiaojishan Formation is a geological formation in Hebei and Liaoning, People's Republic of China, dating to the middle-late Jurassic period (Bathonian-Oxfordian (stage), Oxfordian stages). It is known for its Lagerstätte, exceptionally preser ...

and acquired by the

Beijing Museum of Natural History The National Natural History Museum of China (NNHM; ), previously the Beijing Museum of Natural History, is a municipal public natural history museum in Dongcheng, Beijing, China. It is affiliated with the Beijing Academy of Science and Technolo ...

. The

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

''Agilodocodon scansorius'' was named and described in the journal ''

Science Science is a systematic discipline that builds and organises knowledge in the form of testable hypotheses and predictions about the universe. Modern science is typically divided into twoor threemajor branches: the natural sciences, which stu ...

'' in 2015. The generic name refers to the membership of the Docodonta and the agility. The specific name refers to the scansorial lifestyle.

References

Docodonta Middle Jurassic synapsids of Asia Jurassic China Fossils of China Fossil taxa described in 2015 Taxa named by Qing-Jin Meng Taxa named by Ji Qiang Taxa named by Yu-Guang Zhang Taxa named by Di Liu Taxa named by David M. Grossnickle Taxa named by Zhe-Xi Luo {{paleo-cynodont-stub