Pachyrhachis
Encyclopedia
Pachyrhachis is an extinct genus
of snake
with well developed hind legs known from fossils discovered Ein Yabrud
, near Ramallah
, in the central West Bank
. It is one of three genera of Cenomanian
snakes with hindlimbs. Many of today's modern pythons and boas still have small bone spurs, where limbs would have been millions of years ago. Pachyrhachis snakes would have only been about 1 m (3-4 ft) long. Pachyrhachis was originally described by Haas (1979, 1980) who noted it had a puzzling melange of snake and lizard features; its status as a primitive snake was later confirmed (Caldwell and Lee 1997). The position of Pachyrhachis within snakes is debated (e.g. Lee and Scanlon 2002; Rieppel et al. 2003).
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
with well developed hind legs known from fossils discovered Ein Yabrud
Ein Yabrud
Ein Yabrud is a Palestinian town in the Ramallah and al-Bireh Governorate in the central West Bank. It is located approximately 7 km northeast of the city of Ramallah and its elevation is 800 m. According to the Palestinian Central Bureau of Statistics the town had a population of 3,000...
, near Ramallah
Ramallah
Ramallah is a Palestinian city in the central West Bank located 10 kilometers north of Jerusalem, adjacent to al-Bireh. It currently serves as the de facto administrative capital of the Palestinian National Authority...
, in the central West Bank
West Bank
The West Bank ) of the Jordan River is the landlocked geographical eastern part of the Palestinian territories located in Western Asia. To the west, north, and south, the West Bank shares borders with the state of Israel. To the east, across the Jordan River, lies the Hashemite Kingdom of Jordan...
. It is one of three genera of Cenomanian
Cenomanian
The Cenomanian is, in the ICS' geological timescale the oldest or earliest age of the Late Cretaceous epoch or the lowest stage of the Upper Cretaceous series. An age is a unit of geochronology: it is a unit of time; the stage is a unit in the stratigraphic column deposited during the corresponding...
snakes with hindlimbs. Many of today's modern pythons and boas still have small bone spurs, where limbs would have been millions of years ago. Pachyrhachis snakes would have only been about 1 m (3-4 ft) long. Pachyrhachis was originally described by Haas (1979, 1980) who noted it had a puzzling melange of snake and lizard features; its status as a primitive snake was later confirmed (Caldwell and Lee 1997). The position of Pachyrhachis within snakes is debated (e.g. Lee and Scanlon 2002; Rieppel et al. 2003).
See also
Other known fossil snakes with legs:- EupodophisEupodophisEupodophis is an extinct genus of snake from the Late Cretaceous period. It has two small hind legs and is considered a transitional form between Cretaceous lizards and limbless snakes. The feature, described as vestigial, was most likely useless to Eupodophis. The type species Eupodophis...
- HaasiophisHaasiophisHaasiophis, consisting of the sole species Haasiophis terrasanctus, is an extinct genus of snakes with hind limbs. It is one of three genera of Cenomanian snakes known to have possessed hindlimbs.-Etymology:...
- Najash
