Zalambdalestes (meaning much-like-lambda robber) is an extinct genus of eutherian mammal known from the Upper Cretaceous in Mongolia.

Zalambdalestes
Temporal range: Late Cretaceous
Zalambdalestes lechei skull and lower jaw, Museum of Evolution Warsaw
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: incertae sedis
Family: Zalambdalestidae
Genus: Zalambdalestes
Gregory & Simpson, 1926
Species
  • Z. lechei Gregory & Simpson, 1926 (type)
Life restoration of Z. lechei

Description

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Zalambdalestes was a hopping animal with a long snout, long teeth, a small brain and large eyes. It was about 20 centimetres (7.9 in) long, with a head only 5 centimetres (2 in) long. It had strong front paws and even stronger rear ones, sharing specializations to saltation similar to those of modern rabbits.[1][2] It was most likely not a placental due to the presence of an epipubic bone,[1][3] It had a unique axis that allowed for rapid movements, and in life it might have had spines or bristly fur.[4]

Biology

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Its diet was probably composed mainly of insects that it hunted in the forest undergrowth using its sharp, interlocking teeth.[5] A well-preserved series of cervical vertebrae, including the axis, but not the atlas, seem to suggest vermivory.[4] Unlike modern placental mammals, Zalambdalestes had an epipubic bone, meaning it was probably restricted reproductively in the same way as modern monotremes and marsupials,[1] though a study on multituberculate reproduction suggests early eutherians could give birth to well-developed young.[6] Its unique axis allowed for rapid movements to catch prey.[4]

 
Life reconstruction of Z. lechei

References

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  • Parker, Steve. Dinosaurs: the complete guide to dinosaurs. Firefly Books Inc, 2003. Pg. 402
  1. ^ a b c Rose, Kenneth D.; Archibald, J. David, eds. (2005). The Rise of Placental Mammals: Origins and Relationships of the Major Extant Clades. Johns Hopkins University Press. ISBN 9780801880223.
  2. ^ Chen, Meng; Wilson, Gregory P. (2015). "A multivariate approach to infer locomotor modes in Mesozoic mammals". Paleobiology. 41 (2): 280–312. Bibcode:2015Pbio...41..280C. doi:10.1017/pab.2014.14. S2CID 86087687.
  3. ^ Dykes, Kevin T. "Mesozoic Mammals; Zalambdalestidae, Lipotyphla?, Cimolestidae and Cretaceous Taeniodonta". Mesozoic Eucynodonts. Archived from the original on March 4, 2006.
  4. ^ a b c Arnold, Patrick; Janiszewska, Katarzyna; Li, Qian; O'Connor, Jingmai K.; Fostowicz-Frelik, Łucja (April 16, 2024). "The Late Cretaceous eutherian Zalambdalestes reveals unique axis and complex evolution of the mammalian neck". Science Bulletin. 69 (11): 1767–1775. Bibcode:2024SciBu..69.1767A. doi:10.1016/j.scib.2024.04.027. PMID 38702276.
  5. ^ Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 201. ISBN 1-84028-152-9.
  6. ^ Urton, James (July 25, 2022). "New study challenges old views on what's 'primitive' in mammalian reproduction". UW News. University of Washington. Retrieved April 6, 2024.

Further reading

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