Sphenacanthus
Name:
Sphenacanthus.
Phonetic: Sfen-ah-can-fus.
Named By: Agassiz - 1837.
Synonyms: Ctenacanthus costellatus,
Ctenacanthus hybodioides.
Classification: Chordata, Chondrichthyes,
Elasmobranchii, Xenacanthida.
Species: S. aequistriatus, S.
costellatus, S. hybodioides, S. hybodoides, S. marshi,
S. riorastoensis, S. sanpauloensis, S. serrulatus, S. tenuis.
Diet: Carnivore/Piscivore.
Size: Unavailable.
Known locations: Brazil - Irati Formation, Rio
do Rasto Formation, England, Russia, and Scotland -
Glencartholm Volcanic Beds Formation.
Time period: Famennian of the Devonian through to
the Capitanian of the Permian.
Fossil representation: Several individuals but from
incomplete remains.
Sphenacanthus
is a genus of xenacanthid shark
that has a known temporal range
stretching from the late Devonian period all the way to the late
Permian. Sphenacanthus is believed to have been a
freshwater shark
that inhabited waterways and swamps were individuals likely hunted for
fish, other smaller sharks and possibly amphibians such as
temnospondyls, particularly smaller individuals and juveniles still
in their larval stages.
Sphenacanthus
is so far not known past the Permain/Triassic boundary, possibly
suggesting that the genus died out during the extinction event at this
time, one that was so bad, that more animals died out here than
what happened during the KT extinction sixty-five million years ago
which also marked the end of dinosaurs. A reason for this could be
the gradual mass drying out of the swamps caused by all of the
continents slowly coming together to form the supercontinent of
Pangea. However with that said, other xenacanthid sharks such as
Orthacanthus
and the type genus Xenacanthus
are known to have survived
into the Triassic.
Sphenacanthus
should not be confused with the very similarly named shark
Stethacanthus.
Further reading
- Chondrichthyans from the base of the Irati Formation (Early
Permian, Paran� Basin), S�o Paulo, Brazil - A. Chahud,
T. R. Fairchild & S. Petri - 2010.
- A new species of sphenacanthid (Chondrichthyes,
Elasmobranchii) from the Rio do Rasto Formation (Paran� basin),
southern Brazil - V. E. Pauliv, E. V. Dias &
F.
A. Sedor - 2012.
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