
Acrodonty (from Greek ''akros'' 'highest' + ''odont-'' 'tooth') is an anatomical placement of the teeth at the summit of the
alveolar ridge
The alveolar process () is the portion of bone containing the tooth sockets on the jaw bones (in humans, the maxilla and the mandible). The alveolar process is covered by gums within the mouth, terminating roughly along the line of the mandib ...
of the jaw, without sockets, characteristic of
bony fish
Osteichthyes ( ; ), also known as osteichthyans or commonly referred to as the bony fish, is a Biodiversity, diverse clade of vertebrate animals that have endoskeletons primarily composed of bone tissue. They can be contrasted with the Chondricht ...
. Functionally, acrodont tooth implantation may be related to greater bite force. However, this result is not supported when size and phylogeny is taken into account.
Examples
Squamata
Within
squamate
Squamata (, Latin ''squamatus'', 'scaly, having scales') is the largest Order (biology), order of reptiles; most members of which are commonly known as Lizard, lizards, with the group also including Snake, snakes. With over 11,991 species, it i ...
reptiles, acrodont tooth implantation is best known in
Acrodonta and some species of
amphisbaenia
Amphisbaenia (called amphisbaenians or worm lizards) is a group of typically legless lizards, comprising over 200 extant species. Amphisbaenians are characterized by their long bodies, the reduction or loss of the limbs, and rudimentary eyes. A ...
ns, though some snakes are also referred to as being acrodont. Acrodonta is unique in that the name of the clade is based upon this trait. Most other squamate reptiles have
pleurodont dentition, though some snakes are occasionally described as having acrodont dentition.
Rhynchocephalia
Acrodont tooth implantation is common within
Rhynchocephalia
Rhynchocephalia (; ) is an order of lizard-like reptiles that includes only one living species, the tuatara (''Sphenodon punctatus'') of New Zealand. Despite its current lack of diversity, during the Mesozoic rhynchocephalians were a speciose g ...
, including ''
Sphenodon''.
Amphibia
Acrodont tooth implantation also present in some
frogs
A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough skin texture due to ...
and the
temnospondyl
Temnospondyli (from Greek language, Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') or temnospondyls is a diverse ancient order (biology), order of small to giant tetrapods—often considered Labyrinth ...
''
Microposaurus''.
[Damiani, Ross (2004). "Cranial anatomy and relationships of Microposaurus casei, a temnospondyl from the Middle Triassic of South Africa". Journal of Vertebrate Paleontology. 24 (3): 533–41. doi:10.1671/0272-4634(2004)024 533:caarom.0.co;2.]
References
External links
Tooth ImplantationOral Cavity of Reptiles - Anatomy and Physiology
Dentition types
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