Mixodectidae

Cladus: Eukaryota
Supergroup: Opisthokonta
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Superclassis: Tetrapoda
Classis: Mammalia
Subclassis: Theria
Infraclassis: Placentalia
Ordo: Dermoptera
Familia: † Mixodectidae
Genera: Mixodectes - Dracontolestes

Name

Mixodectidae (Cope, 1883)

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Mixodectidae or mixodectids (from Greek μιξο, mixo, "mixed", and δεκτες, dektes "biter") is an extinct family of insectivore, placental mammals in the order Dermoptera. The Mixodectids originated in the late Cretaceous and survived into the Paleocene in Europe and North America.[2]
Description

While there are 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, 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.

[2]

Torrejonian (Middle Paleocene) Mixodectidae had a dental set-up similar to the oldest Plagiomenids and is 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 specialization similar to those of Plesiadapiformes and Dermopterans, supporting their inclusion within Euarchonta.

[3]

Notes

1. ^ a b "Mixodectidae". Paleobiology Database. http://www.paleodb.org/cgi-bin/bridge.pl?action=checkTaxonInfo&taxon_no=40331&is_real_user=1. Retrieved January 2010.
2. ^ a b Agusti (2002) p 5
3. ^ Rose 2006, p 164

References

* Agusti, Jordi; Anton, Mauricio (2002). Mammoths, Sabertooths, and Hominids: 65 Million Years of Mammalian Evolution in Europe. Columbia University Press. ISBN 0231116403.
* Rose, Kenneth David (2006). The beginning of the age of mammals. JHU Press. ISBN 0801884721. http://books.google.com/books?id=3bs0D5ix4VAC&pg.