The genus " Heloderma " has existed since the Miocene, when " H . texana " lived, and fragments of osteoderms from the Gila monster have been found in late Pleistocene ( 8, 000-10, 000 years ago ) deposits near Las Vegas, Nevada.
12.
It includes " Heloderma ", as well as several extinct genera, such as " Estesia " and " Gobiderma ", but it was found to be polyphyletic in the most recent and complete squamate phylogenetic analysis by Reeder " et al . " ( 2015 ).
13.
It is also home to a number of threatened lizards, including the Guatemalan Spiny-tailed Iguana ( " Ctenosaura palearis " ), and the Motagua Valley beaded lizard ( " Heloderma horridum charlesbogerti " ), one of the world's most endangered lizards which is endemic to this ecoregion.
14.
Has been described as " des-38-proline-exendin-4 ( " Heloderma suspectum " )-( 1 39 )-peptidylpenta-L-lysyl-L-lysinamide ", meaning it is derived from the first 39 amino acids in the Gila monster venom, omitting proline at position 38 and adding six lysine residues.
15.
Of these it is known that 13 are endemic to the western and central region of Mexico : the rattlesnake, the black iguana, the frog " Shyrrhopus modestus ", the beaded lizard ( " Heloderma horridum " ) and the Autlan rattlesnake ( " Crotalus lannomi " ), an endemic species only reported for the area of Puerto de Los Mazos.
16.
Although he originally assigned it the generic name " Trachyderma ", he changed it to " Heloderma " six months later, which means " studded skin ", from the Ancient Greek words " h�los " ( ???? ) & mdash; the head of a nail or stud & mdash; and " derma " ( ????? ), meaning skin.
17.
In terms of herpetofauna, 85 species have been recorded; of these 13 are endemic to the western and central region of Mexico : rattlesnake, black iguana, frog " Shyrrhopus modestus ", beaded lizard ( " Heloderma horridum " ) and the Autlan rattlesnake ( " Crotalus lannomi " ), an endemic species only reported for the area of Puerto de Los Mazos.
18.
In terms of herpetofauna, 85 species have been recorded; of these it is known that 13 are endemic to the western and central region of Mexico : the rattlesnake, the black iguana, the frog " Shyrrhopus modestus ", the beaded lizard ( " Heloderma horridum " ) and the Autlan rattlesnake ( " Crotalus lannomi " ), an endemic species only reported for the area of Puerto de Los Mazos.
