World Library  
Flag as Inappropriate
Email this Article

Cladoselache

Article Id: WHEBN0000969150
Reproduction Date:

Title: Cladoselache  
Author: World Heritage Encyclopedia
Language: English
Subject: Chondrichthyes, Evolution of fish, Shark, Devonian, Time range of Hexanchiformes species
Collection: Devonian Sharks, Prehistoric Fish of North America
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Cladoselache

Cladoselache
Temporal range: Late Devonian
Є
O
S
D
C
P
T
J
K
Pg
N
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Order: Cladoselachiformes
Family: Cladoselachidae
Genus: Cladoselache
Dean, 1894
Species
  • Cladoselache acanthopterygius
  • Cladoselache brachypterygius
  • Cladoselache clarkii
  • Cladoselache desmopterygius
  • Cladoselache elegans
  • Cladoselache fyleri
  • Cladoselache kepleri
  • Cladoselache magnificus
  • Cladoselache mirabilis
  • Cladoselache newmani
  • Cladoselache pattersoni

Cladoselache is a genus of extinct shark. It appeared in the Devonian period.

This primitive shark grew to be up to 6 feet (1.8 m) long and roamed the oceans of North America. It is known to have been a fast moving and fairly agile kidneys.[1]

Contents

  • Appearance 1
  • Palaeobiology 2
  • References 3
  • Sources 4
  • External links 5

Appearance

Cladoselache fyleri

Cladoselache exhibited a combination of derived and ancestral characteristics. It had anatomical features similar to the current mackerel sharks of the family Lamnidae.

It had a streamlined body, from five to seven gill slits, and a short, rounded snout that had a terminal mouth opening at the front of the skull.[1] It had a very weak jaw joint compared with modern-day sharks, but it compensated for that with very strong jaw-closing muscles. Its teeth were multi-cusped and smooth-edged, making them suitable for grasping, but not tearing or chewing. Cladoselache therefore probably seized prey by the tail and swallowed it whole.

Its sturdy but light-weight fin spines were composed of dentine and enamel.[1] Cladoselache also had a blade-like structure which was positioned in front of the dorsal fins. These anatomical features made swimming easier and faster.

Unlike most sharks, Cladoselache was almost entirely devoid of scales with exception of small cusped scales on the edges of the fins, mouth and around the eyes. It also had powerful keels that extended onto the side of the tail stalk and a semi-lunate tail fin, with the superior lobe about the same size as the inferior.[1] This combination helped with its speed and agility which was useful when trying to outswim its probable predator, the heavily armored 10 metres (33 ft) long placoderm fish Dunkleosteus.

Palaeobiology

Members of the Cladoselache genus were predatory sharks, and the well preserved fossils found on the Cleveland Shale revealed a significant amount regarding their eating habits. Within the gut of most Cladoselache fossils were remnants of their stomach contents. These remains included mostly small ray-finned bony fishes, as well as shrimp-like fish and hagfish-like proto-vertebrates. Some of the fish remains were found tail first within the stomach, indicating that Cladoselache was a fast and agile hunter.

A mystery that has yet to be resolved is its method of reproduction. Cladoselache lacked sperm during reproduction. This is peculiar given that most other early shark fossils show evidence of claspers. While they may have used internal fertilization, this has yet to be demonstrated.

References

  1. ^ a b c d Palmer, D., ed. (1999). The Marshall Illustrated Encyclopedia of Dinosaurs and Prehistoric Animals. London: Marshall Editions. p. 26.  

Sources

  • Ferrari, Andrea; Ferrari, Antonella (2002). Sharks.  
  • Maisey, John. G. (June 1998). "Voracious Evolution". Natural History 107 (5): pp. 38–41. 

External links

  • Cladoselache ReefQuest Centre for Shark Research. Retrieved 10 February 2012.
  • Monastersky, Richard (1996) The first shark: to bite or not to bite Science News, 149 (7): 101.
  • The Evolution of Sharks
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 



Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.