Saniwa
|
Saniwa Temporal range: Eocene, 48 Ma |
|
|---|---|
 |
|
| Skeleton of Saniwa ensidens in the Field Museum of Natural History | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Squamata |
| Family: | Varanidae |
| Genus: |
†Saniwa Leidy, 1870 |
| Species | |
|
|
| Synonyms | |
|
|
Saniwa is an extinct genus of monitor lizards that lived during the Eocene epoch around 48 million years ago. Well-preserved fossils have been found in the Bridger and Green River Formations of Wyoming, and evidence indicates Saniwa also lived in Europe. The type species S. ensidens was named in 1870 as the first fossil lizard known from North America. Several other species have since been added, but their validity is uncertain. It is a close relative of Varanus, the genus that includes extant monitor lizards.
Saniwa grew to around 1.3 m (4.3 ft) in length, though S. grandis could reach 2.15 m (7.1 ft). Like other monitor lizards, Saniwa has a long, pointed snout and nostrils placed farther back in the skull than most lizards. The tail is almost twice as long as the rest of the body. Although similar in appearance to living monitor lizards, Saniwa has several primitive traits, including teeth on its palate, a jugal bone beneath the eye that extends farther forward, and a suture between the frontal and parietal bones that is straight rather than curved or wavy.
In 1870, American geologist Ferdinand Vandeveer Hayden found the first fossils of Saniwa near the town of Granger, Wyoming, and gave them to paleontologist Joseph Leidy. Later that year, Leidy described the type species Saniwa ensidens on the basis of these fossils. Saniwa was the first extinct lizard to be named from North America. The first remains of S. ensidens were preserved as black bones in marl that was part of the Bridger Formation. Hayden suggested the name Saniwa to Leidy because it was "used by one of the Indian tribes of the Upper Missouri for a rock-lizard." Leidy saw a close similarity between Saniwa and the living Nile monitor.
...
Wikipedia