Mixodectidae (from Greek μιξο, ''mixo'', "mixed", and δεκτες, ''dektes'' "biter") is an extinct family of

insectivorous A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores were ...

placental mammal Placental mammals ( infraclass Placentalia ) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupialia. Placentalia contains the vast majority of extant mammals, which are partly distinguish ...

s in the order Dermoptera. The mixodectids originated in the late

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

and survived into the

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...

in Europe and North America.

Description

While there is less anatomical evidence for this group than for other archaic placental families (such as apatemyids, pantolestids, leptictids, and palaeoryctids), preserved dental and cranial anatomies give an idea of mixodectid dietary requirements. Their rodent-like dental pattern was similar to that of the

multituberculates Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the Middle Jurassic, ...

, with a pair of large, strong, and forward-directed incisors and a row of multi-cusped and low-crowned premolars and molars a specialized dental set-up probably used for crushing and opening hard seeds and nuts.

Torrejonian The Torrejonian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages The North American land mammal ages (NALMA) establishes a geologic timescale for North American fa ...

(Middle Paleocene) Mixodectidae had a dental set-up similar to the oldest plagiomenids and are therefore supposedly an ancestral or sister group of the latter. For many years '' Elipdophorus'', the oldest plagiomenid, was classified as Mixodectidae but was finally regarded as more closely related to plagiomenids in the 1970s based on derived dental resemblances. Though the relation between Mixodectidae and other early placental mammals from the "insectivore-primate transition" remain unclear, clearly a number of the archaic mixodectid dental features seem to foreshadow the more derived conditions of plagiomenids. Furthermore, the postcranial skeleton of '' Mixodectes'' shows

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose num ...

specialization similar to those of plesiadapids and dermopterans, supporting their inclusion within

Euarchonta The Euarchonta are a proposed grandorder of mammals: the order Scandentia (treeshrews), and its sister Primatomorpha mirorder, containing the Dermoptera or colugos and the primates (Plesiadapiformes and descendents). The term "Euarchonta" (m ...

Notes

References

* *

External links

* {{Taxonbar, from=Q2599736 Prehistoric placental mammals Paleocene mammals Prehistoric mammals of North America Prehistoric mammals of Europe Paleocene first appearances Paleocene extinctions Fossil taxa described in 1883 Prehistoric mammal families

Description

See also

Notes

References

External links