Cretolamna

Cretolamna
Temporal range: Cretaceous–Eocene
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Superorder: Selachimorpha
Order: Lamniformes
Family: †Otodontidae
Genus: †Cretolamna
Species
  • Cretolamna appendiculata
  • Cretolamna appendiculata appendiculata
  • Cretolmana appendiculata pachyrhiza
  • Cretolamna aschersoni
  • Cretolamna biauriculata
  • Cretolamna gunsoni
  • Cretolamna lata
  • Cretolamna maroccana
  • Cretolamna pachyrhiza

Cretolamna[1] is an extinct mackerel shark which lived during the Cretaceous and Paleogene periods, during the Paleocene and Eocene epochs, approximately 90 to 50 million years ago.[2]

Size estimation

The fossils of Cretolamna are of teeth and a few scattered vertebrae. Most teeth average about 1 to 2 cm (about .5 to .75 in) long. Most estimates put the shark's length at about 2–3 m (7–10 feet) long with the largest specimens being about 3.6 m (12 feet) in length.[3]

Distribution

Cretolamna was a widespread genus in North Africa (Morocco) and North America on the East Coast and in the Midwest. Deposits in Morocco are usually Eocene in age, while most deposits in the U.S. are of Cretaceous and Paleocene age.[4] C. maroccana is more prevalent in Morocco. C. appendiculata is more prevalent in the United States. Both species overlapped at one point in time.

Diet

Cretolamna was a predator and preyed upon large bony fish, turtles, mosasaurs, squids, and other sharks. It was a medium-sized predatory shark.[5]

Evolution

Cretolamna is believed to have evolved into the Otodus genus sometime in the Paleocene. Otodus is believed to have evolved later into the Carcharocles genus. Others believe that Cretolamna evolved into the Paleocene shark Palaeocarcharodon, which would evolve into Carcharodon carcharias.[6]

See also

References

  1. ↑ The spelling of the name is controversial; the original spelling is Cretalamna, but currently both spellings are in use. For comments on the spelling of the genus name see: Mikael Siverson, Johan Lindgren, Michael G. Newbrey, Peter Cederström and Todd D. Cook (2013). "Late Cretaceous (Cenomanian-Campanian) mid-palaeolatitude sharks of Cretalamna appendiculata type". Acta Palaeontologica Polonica. in press. doi:10.4202/app.2012.0137.
  2. ↑ Welton & Farish, Bruce J. & Roger F. (1993). The Collectors's Guide to Fossil Sharks and Rays from the Cretaceous of Texas. Before Time.
  3. ↑ Yoost, Derek. "Porbeagle Sharks". Retrieved 14 May 2012.
  4. ↑ Yoost, Derek. "Potomac River Fossils". Retrieved 14 May 2012.
  5. ↑ Kent, Bretton W. (1987). Fossil Sharks of the Chesapeake Bay Region. Egan Rees & Boyer Inc.
  6. ↑ "Carcharodon Megalodon". Retrieved 14 May 2012.