Have Mouth, Will Eat. -- The Tiger shark is a circumglobal predator-scavenger. Favoring tropical and warm-temperate seas, this common coastal-pelagic species may be found in near-shore (estuaries & lagoons) and off-shore (to 140 M) waters of the continental & insular shelf. It is a large (usually less then 5, but reported to 7.4 M), active species and a strong swimmer. Probably the least specialized feeder amongst the sharks, Compagno (1984) reported its diet to include: bony fish (from eels to tarpon), sharks & batoids, marine reptiles (turtles & sea snakes), sea birds, marine mammals, invertebrates (cephalopods, crustaceans, gastropods & jellyfish), carrion and various otherwise inedible objects (human & natural trash).

The teeth of this dentition (gradient monognathic heterodonty) are reminiscent of a can-opener. They incorporate a triangular, distally directed cusp and a prominent distal heel. The heel usually bears cusplets and it (and the cusp's cutting-edge) is serrate (stronger basally). The crown's lingual face is convex, and the relatively flat labial face, overhangs the root. There is a well marked lingual protuberance and weak groove. The roots of medial teeth are much thicker than their lateral counterparts.

Tiger sharks have a fossil record dating to the Early Eocene. Cappetta (1987:123-25) included several species:

  • G. latidens (AGASSIZ 1843) in the Eocene of Africa, Europe & North America.
  • G. eaglesomei WHITE 1955 from the Middle Eocene Africa & the Arabian Peninsula. (Case & Borodin 2000 included this species in the Eocene of North Carolina.)
  • G. mayumbensis DARTEVELLE & CASIER 1943 Miocene of Cabinda (western Africa), he noted its similarity to the teeth of G. eaglesomi.
  • Galeocerdo aduncus AGASSIZ 1843 known form the Lower Oligocene - Miocene of Europe, Miocene of Africa, North & South America and India, and from the Miocene and Pliocene of Japan.
  • G. contortus GIBBES 1849 from the Miocene of the US (not Europe). Ward & Bonavia (2001:138) moved this species from Galeocerdo to Physogaleus based on tooth-design — elasmo.com concurs with this observation.
  • G. cuvier (PERON & LESUEUR 1822) the extant species from the Pliocene of Europe, Africa and North America.

    The Eocene species, Galeocerdo latidens is found throughout the Atlantic Coastal Plain. In the Nanjemoy, it has not been reported from Potapaco sediments, but Ward & Weist (1990) included the species in the Woodstock Member (Early Eocene) and Piney Point Formation (Middle Eocene) of Maryland and Virginia. These teeth are regularly collected in the Castle Hayne of No. Carolina, and Eocene exposures of So. Carolina.

    The Physogaleus-like tooth-design of contortus is not only abundant in Mid-Atlantic Miocene sediments, such as the Pungo River & Calvert Formations, but appear to be present (pers. obs.) in the Oligocene sediments of the Chandler Bridge (SC) and Old Church (VA) Formations. Although rarely reported from the No. American Pacific coast, contortus teeth have been recovered from the southern California area (Heim pers. com.). The teeth of Galeocerdo aduncus are abundant in the Pungo River and there is on-going speculation as to whether or not the teeth of contortus may be a sexual or other variations of the aduncus tooth-design. On this website, contortus teeth are included in the Physogaleus page.

    Other Website References

    A Lee Creek Fauna page on Galeocerdo spp from Heim on Sharks
    Bill Heim on tiger shark Lineages
    Bill Heim on tiger shark Teeth
    Richard Chandler on the G. cuvier Lineage

     

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