Adapidae is a family of extinct primates that primarily radiated during the
Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...
epoch between about 55 and 34 million years ago.
Adapid systematics and evolutionary relationships are controversial, but there is fairly good evidence from the postcranial skeleton (everything but the skull, or cranium) that adapids were stem strepsirrhines (members of the group including the living lemurs, lorises, and bushbabies). In particular, the anatomy of the adapid wrist and ankle (e.g., position of the groove for the flexor fibularis tendon on the talus, the presence of a sloping talo-fibular facet) show derived similarities with those of living strepsirrhines. However, adapids lacked many of the anatomical specializations characteristic of living strepsirrhines, such as a
toothcomb
A toothcomb (also tooth comb or dental comb) is a dental structure found in some mammals, comprising a group of front teeth arranged in a manner that facilitates grooming, similar to a hair comb. The toothcomb occurs in lemuriform primates ...
,
[Rose, K. D., A. Walker, and L. L. Jacobs. 1981. Function of the mandibular tooth comb in living and extinct mammals. Nature 289:583-585.] a
toilet-claw
A grooming claw (or toilet claw) is the specialized claw or nail on the foot of certain primates, used for personal grooming. All prosimians have a grooming claw, but the digit that is specialized in this manner varies. Tarsiers have a grooming ...
on the second pedal digit, and a reduction in the size of the promontory branch of the internal carotid artery.
There are two major branches of adapids, subfamily
Adapinae
Adapinae is a subfamily within the extinct primate family Adapidae primarily found in Europe until the end of the Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second ...
(adapines) and subfamily
Caenopithecinae
Caenopithecinae is a subfamily within the extinct primate family Adapidae, found in Europe and northern Africa from the Eocene to the Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 milli ...
(caenopithecines). Caenopithecines are sometimes assigned to their own family, Caenopithecidae.
References
Prehistoric strepsirrhines
Eocene primates
Eocene first appearances
Eocene extinctions
Prehistoric mammal families
Primate families
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