Physogaleus is an extinct genus of small requiem shark[2] that lived from the Late Paleocene[1] to Miocene epochs.[3][4]

Physogaleus
Temporal range: Upper Thanetian-Burdigalian 56–15.97 Ma
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Subdivision: Selachimorpha
Order: Carcharhiniformes
Genus: Physogaleus
Cappetta, 1980
Type species
Physogaleus secundus
(Winkler, 1876)
Species
  • Physogaleus americanus Case, 1994
  • Physogaleus contortus (Gibbes, 1849)
  • Physogaleus hemmooriensis Reinecke & Hoedemakers, 2006
  • Physogaleus huberensis (Case, 1981)
  • Physogaleus latecuspidatus Muller, 1999
  • Physogaleus latus (Storms, 1894)
  • Physogaleus maltzani (Winkler, 1875)
  • Physogaleus onkensis Boulemia & Adnet, 2023[1]
  • Physogaleus rosehillensis Case & Borodin, 2000
  • Physogaleus secundus (Winkler, 1876)
  • Physogaleus tertius (Winkler, 1876)

Description edit

Physogaleus is only known from fossil teeth and isolated vertebra. The teeth similar to those of the modern Tiger shark, but are smaller, with a more central cusp that projects farther from the base of the tooth. The species of Physogaleus were originally described as belonging to the same genus as the modern Tiger shark, Galeocerdo. Recognition of numerous differences in dental anatomy of each these species compared other species of Galeocerdo lead researchers to erect the genus Physogaleus to include taxa that were more morphologically similar to one another than they were to Galeocerdo.[5]

Physogaleus teeth reach a maximum size that is smaller than that of true tiger sharks, and they lack the heavy serrations typical of Galeocerdo. They are also are more slender and the central cusp can be somewhat twisted toward the crown. This indicates individuals of Physogaleus probably had a diet of bony fish, similar to the living sand-tiger shark.[4]

References edit

  1. ^ a b S. Boulemia, S. Adnet (2023). "A new Palaeogene elasmobranch fauna (Tebessa region, eastern Algeria) and the importance of Algerian-Tunisian phosphates for the North African fossil record". Annales de Paléontologie. 109 (3). Bibcode:2023AnPal.10902632B. doi:10.1016/j.annpal.2023.102632. S2CID 264571594.
  2. ^ D. J. Cicimurri, J. L. Knight, J. A. Ebersole (March 2022). "Early Oligocene (Rupelian) fishes (Chondrichthyes, Osteichthyes) from the Ashley Formation (Cooper Group) of South Carolina, USA". PaleoBios. 39 (1): 1–38. doi:10.5070/P939056976.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  3. ^ Reinecke, Thomas; Hoedemakers, Kristiaan (2006). "Physogaleus hemmooriensis (Carcharhinidae, Elasmobranchii) A New Shark Species from the Early to Middle Miocene of the North Sea Basin". PalaeoVertebrata. 34 (1–2): 1–25.
  4. ^ a b "Tiger Shark Facts and Information". Fossilguy.
  5. ^ Hernandez, C. 2015. Paleobiology of the Mio-Pliocene sharks, with emphasis on the extinct apex predator Carcharocles megalodon. University of Florida. Unpublished Ph.D. Dissertation