Lizards and snakes represent scaled reptiles (squamata). Lizard development involves an amniotic egg, that evolutionary (~320 million years ago) freed the vertebrates from their aquatic (water) to a terrestrial (land) environment.
The genome of the lizard Anolis carolinensis (green anole) from southeastern United States has a karyotype of 18 chromosomes, comprising six pairs of large macrochromosomes and 12 pairs of small microchromosomes, and has recently been sequenced . Interestingly, almost all reptilian genomes also contain "microchromosomes", very small chromosomes less than 20 Mb in sequence size. (More? Genome)
Some Recent Findings
root; cellular organisms; Eukaryota; Opisthokonta; Metazoa; Eumetazoa; Bilateria; Coelomata; Deuterostomia; Chordata; Craniata; Vertebrata; Gnathostomata; Teleostomi; Euteleostomi; Sarcopterygii; Tetrapoda; Amniota; Sauropsida; Sauria; Lepidosauria
Squamata (squamates) - snakes and lizards.
- Iguania (iguanian lizards) - arboreal with primitively fleshy, non-prehensile tongues, highly modified in the chameleons.
- Iguanidae (iguanid lizards)
- Anguimorpha (anguimorph lizards)
- Gekkota - all geckos and the limbless Pygopodidae.
- Scincomorpha (scincomorph lizards)
- Serpentes (snakes)
- unclassified Squamata
- Links: Taxonomy Browser Lizards
Australian Water Skink
Anolis carolinensis (green anole)
The genome of the lizard Anolis carolinensis (green anole) from southeastern United States has a karyotype of 18 chromosomes, comprising six pairs of large macrochromosomes and 12 pairs of small microchromosomes, and has recently been sequenced . Interestingly, almost all reptilian genomes also contain "microchromosomes", very small chromosomes less than 20 Mb in sequence size.
It is a model organism for laboratory-based studies of organismal function and for field studies of ecology and evolution. This species was chosen for genome sequencing in part because of the ease and low expense of captive breeding, well studied brain, and sophisticated color vision. It is also well suited for studies involving the role of hormones in development and adult nervous system plasticity. (modified from Genome)
Search PubMed Genome: Lizard
Schwalbe (1891) points out the significant fact that in reptiles that lack an external ear (lizard and turtle) there occur distinct hillocks in the embryo, resembling those in vertebrates that develop an auricle. These hillocks undergo degeneration and are reduced to the level of the surrounding skin. He finds in both birds and reptiles hillocks corresponding to the tragus and antitragus hillocks of His. These animals have one hillock (Auricularkegel), situated dorsal to the first cleft, which seems to represent a more primitive apparatus than is present in mammals, although it may be related to the helix system. In Salachians it possesses a spiracle.
- <pubmed>22174948</pubmed>| PMC3184186
<pubmed>19645023</pubmed> <pubmed>19097047</pubmed> <pubmed>17415759</pubmed> <pubmed>15521466</pubmed> <pubmed>5437480</pubmed> <pubmed>6429113</pubmed>
Search PubMed: Lizard development
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Cite this page: Hill, M.A. (2021, September 26) Embryology Lizard Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Lizard_Development
- © Dr Mark Hill 2021, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G