Ptychodus

Ptychodus
Temporal range: Early-Late Cretaceous 105–75 Ma
Complete specimen of Ptychodus sp. (MMSP CPC 3064) from Agua Nueva Formation
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Order: Lamniformes
Family: †Ptychodontidae
Jaekel, 1898
Genus: †Ptychodus
Agassiz, 1835
Type species
Ptychodus latissimus
Agassiz, 1835
Other species
List
  • Ptychodus altior Agassiz, 1839
  • Ptychodus anonymus Williston, 1900
  • Ptychodus arcuatus Agassiz, 1837
  • Ptychodus articulatus Agassiz, 1837
  • Ptychodus atcoensis Carrillo-Briceno, 2013
  • Ptychodus belluccii Bonarelli, 1899
  • Ptychodus concentricus Agassiz, 1839
  • Ptychodus decurrens Agassiz, 1839
  • Ptychodus elevatus Leriche, 1929
  • Ptychodus gibberulus Agassiz, 1837
  • Ptychodus janewayii Cope, 1874
  • Ptychodus mahakalensis Chiplonkar and Ghare, 1977
  • Ptychodus mammillaris Agassiz, 1839
  • Ptychodus marginalis Agassiz, 1839
  • Ptychodus mortoni Agassiz, 1843
  • Ptychodus multistriatus Woodward, 1889
  • Ptychodus oweni Dixon, 1850
  • Ptychodus paucisulcatus Dixon, 1850
  • Ptychodus polygyrus Agassiz, 1839
  • Ptychodus rugosus Dixon, 1850
  • Ptychodus spectabili Agassiz, 1837
  • Ptychodus whipplei Marcou, 1858

Ptychodus (from Greek: πτυχή ptyche 'fold' and Greek: ὀδούς odoús 'tooth')[1] is a genus of extinct large durophagous (shell-crushing) lamniform sharks from the Cretaceous period, spanning from the Albian to the Campanian.[2] Fossils of Ptychodus teeth are found in many Late Cretaceous marine sediments worldwide.[3]

At least 16 species are considered valid, with the largest members of the genus suggested to have grown up to 10 meters (33 feet) long.[2] The youngest remains date to around 75 million years ago. A large number of remains have been found in the former Western Interior Seaway.[4][5]

  1. ^ Roberts, George (1839). An etymological and explanatory dictionary of the terms and language of geology. London: Longman, Orme, Brown, Green, & Longmans. p. 144. Retrieved 31 December 2021.
  2. ^ a b Cite error: The named reference :1 was invoked but never defined (see the help page).
  3. ^ The paleobioloy Database Ptychodus entry accessed on 8/23/09
  4. ^ Everhart, Mike. "Ptychodus mortoni". Ocean of Kansas.
  5. ^ "THE VERTEBRATE FAUNA OF THE SELMA FORMATION OF ALABAMA" (PDF). 3 (7). 1970. {{cite journal}}: Cite journal requires |journal= (help)