Acrodonta are a subclade of
iguaniansquamates consisting almost entirely of Old World taxa. Extant representation include the families
Chamaeleonidae (chameleons) and
Agamidae (dragon lizards), with at least over 500 species described. A fossil genus, Gueragama, was found in
Brazil, making it the only known
American representative of the group.[1]
The group is eponymously named from their
acrodont dentition, whereby the teeth are consolidated with the summit of the
alveolar ridge of the jaw without sockets.[2] There are, however, other animals that have acrodont dentition such as
tuataras.[3]
Systematics
Usually acrodonts are divided into two families Chamaeleonidae and Agamidae, there are a few studies that suggest chameleons are nested within Agamidae.[4][5] In order to maintain the familial status of Chamaeleonidae some authors suggested placing the clades
Uromastycinae and
Leiolepidinae in a third family Leiolepididae.[4][5] However a majority of papers concerning acrodont phylogenetics support the traditional dichotomy of the group.[6][7][8][9]
The Acrodonta (lizard) is the oldest iguanian lizard from the African continent. Scientists just discovered new fossils of this lizard that date all the way back to the Mesozoic Era. This indicates that Acrodontan lizards had a widespread geographical distribution in Gondwana, the supercontinent that included Africa. Meaning that they had a extensive role in the evolution of lizards especially iguanas.
Below is the phylogeny of the acrodont lineages after Pyron et al. (2013):[8]
The extinct
Arretosauridae (
Paleogene iguanians from Central Asia) are also sometimes classified in Acrodonta. However, other studies instead suggest it to be a sister group to the
Crotaphytidae in
Pleurodonta.[10][11]
<refVullo, R., Bailon, S., Dauphin, Y., Monchot, H., & Allain, R. (2023, March). A reappraisal of Jeddaherdan Aleadonta (squamata: Acrodonta), the purported oldest iguanian lizard from Africa. NASA/ADS.
https://ui.adsabs.harvard.edu/abs/2023CrRes.14305412V/abstract/ref>
^
abHonda M, Ota H, Kobayashi M, Nabhitabhata J, Yong HS, Sengoku S, Hikida T (2000). "Phylogenetic Relationships of the Family Agamidae (Reptilia: Iguania) Inferred from Mitochondrial DNA Sequences". Zoological Science. 17 (4): 527–537.
doi:
10.2108/zsj.17.527.
hdl:2433/57223.
^
abJacques A. Gauthier; Maureen Kearney; Jessica Anderson Maisano; Olivier Rieppel; Adam D.B. Behlke (2012). "Assembling the Squamate Tree of Life: Perspectives from the Phenotype and the Fossil Record". Bulletin of the Peabody Museum of Natural History. 53 (1): 3–308.
doi:
10.3374/014.053.0101.
S2CID86355757.
^Zheng, Yuchi; Wiens, John J. (2016). "Combining phylogenomic and supermatrix approaches, and a time-calibrated phylogeny for squamate reptiles (lizards and snakes) based on 52 genes and 4162 species". Molecular Phylogenetics and Evolution. 94 (Pt B): 537–547.
doi:
10.1016/j.ympev.2015.10.009.
PMID26475614.