Laytonia

Laytonia
Temporal range: Zemorrian to Upper Miocene[1]
L. californica and Bolbocara
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Superclass: Osteichthyes
Class: Actinopterygii
Order: Notacanthiformes
Family: Halosauridae
Genus: Laytonia
Type species
Laytonia californica
David 1943
Species
  • L. californica
  • L. zemorrensis David 1948

Laytonia is an extinct genus of prehistoric halosaur that lived in deep water off the North American Pacific Coast from the Zemorrian Epoch (comprising either the latest Oligocene or lower Miocene) until during the Upper Miocene subepoch, when tectonic uplift effectively destroyed the genus' habitat by making the deep water too shallow.[2]

There are two species recognized, the type species, L. californica, which is known from at least 2 whole fossils, and fossil scales from Upper Miocene strata of Southern California, and L. zemorrensis, known from fossil scales in Zemorrian strata (either Oligocene or Lower Miocene) from Oregon and California.

According to the fossils of L. californica, the living animals were very slender, and had a long, fringe-like dorsal fin running almost the entire length of the body, from the head to the tip of the tail. The dorsal fin forms two crests, a first, low crest on top of the back of the head, and a second, large crest near the upper back, above the pectoral fins.

The name comes from discoverer of the fossil, Melvin E. Layton.

See also

References

  1. ↑ David, Lore "Halosauridae from the California Tertiary" 1948
  2. ↑ David, Lore Rose. January 10, 1943. Miocene Fishes of Southern California The Society
This article is issued from Wikipedia - version of the Monday, February 22, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.