| Taeniolabidoidea | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | † Multituberculata |
| Superfamily: | † Taeniolabidoidea |
| Family: | † Lambdopsalidae Chow and Qi, 1978 [1] |
| Genera | |
Lambdopsalidae is a family of extinct multituberculate mammals from the Late Paleocene of Asia. They are part of Taeniolabidoidea, a clade otherwise present in the Early Paleocene (and possibly the Late Cretaceous) of North America. The Lambdopsalids probably evolved from a single radiation that spread into Asia from North America in the mid-Paleocene or earlier. They are represented by the genera Lambdopsalis , Sphenopsalis and Prionessus . [2] [1] This group was first defined in 1978 by Chow and Tao Qi. [3]
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The Lambdopsalids were small mammals, with estimated adult body masses of about 0.4 kilograms (0.88 lb) to 0.8 kilograms (1.8 lb). [4] They are notable for their enlarged teeth that implies adaptations towards leaf grazing, [2] and adaptations for burrowing such as a short and flat snout, robust humeri, stiff neck and enlarged lower incisors. [5] [6] This group has a shared dental formula of 2.0.1.21.0.1.2 [3] Examples of Lambdopsalis are notable for offering direct evidence of hair and enamel and tooth prism patterns among multituberculates. [7]
Lambdopsalids lived during the Thanetian, the last stage of the Paleocene, with fossils ranging from 59-55 million years ago. [8] They disappeared around the PETM.
