Synapsid: Difference between revisions

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'''Synapsida''' was a pre-mammalian reptile and believed to be the ancestor of mammals due to the similar shape of their skulls. Synapsida were the dominant land animals of the Late Carboniferous (Pennsylvanian) period to the Permian period which we start to see from about 300 million years ago, though they were more abundant and more diversified in the beginning of the Permian period, around 270 million years ago.
'''Synapsida''', mammal-like reptiles, are believed to have led to the evolution of mammals. Synapsida rose to power during the Late Carboniferous (Pennsylvanian) period and continued to be the predominant land vertebrate through the Permian and Triassic periods.
Prior to the development of the synapsid type skull, reptiles had a low, flat head with jaw muscles that were arranged in such a way to allow their jaws to snap together, but not to bite together in a hard pressing motion. Thus their diets and actions were very limited. With the development of the synapsid skull many other environmental niches were opened up, drastically changing the way that the environment lived and evolved, such as plants which required the evolution of better defensive characteristics.  
 


==Classification==
==Classification==
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==Dentition==
==Dentition==
 
The mammal-like reptiles developed the heterodont shaped dentition with sharp edged incisors for cutting, pointed canines for tearing, and cheek teeth with flat crushing surfaces for chewing. Though they still retained the typical reptilian characteristic of replacing old and worn teeth with new teeth, as the synapsids evolved they gained the ability to keep their teeth longer. Because they were able to keep their teeth longer they were capable of developing more specialized dentition and a better precision bite. This allowed for their food to be chewed down to a pulp, easier to swallow, and thus better to digest. This, in turn, allowed for the nutrients from the food to be released and used by the body much more quickly.


==Warm Bloodedness==
==Warm Bloodedness==

Revision as of 14:43, 16 March 2008

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Synapsida, mammal-like reptiles, are believed to have led to the evolution of mammals. Synapsida rose to power during the Late Carboniferous (Pennsylvanian) period and continued to be the predominant land vertebrate through the Permian and Triassic periods. Prior to the development of the synapsid type skull, reptiles had a low, flat head with jaw muscles that were arranged in such a way to allow their jaws to snap together, but not to bite together in a hard pressing motion. Thus their diets and actions were very limited. With the development of the synapsid skull many other environmental niches were opened up, drastically changing the way that the environment lived and evolved, such as plants which required the evolution of better defensive characteristics.


Classification

Pelycosauria

Pelycosauria was the earliest and most primitive of the synapsida reptiles, and thought to have roamed the earth as early as 300 million years ago during the Late Carboniferous.

Therapsida

The Skull

Dentition

The mammal-like reptiles developed the heterodont shaped dentition with sharp edged incisors for cutting, pointed canines for tearing, and cheek teeth with flat crushing surfaces for chewing. Though they still retained the typical reptilian characteristic of replacing old and worn teeth with new teeth, as the synapsids evolved they gained the ability to keep their teeth longer. Because they were able to keep their teeth longer they were capable of developing more specialized dentition and a better precision bite. This allowed for their food to be chewed down to a pulp, easier to swallow, and thus better to digest. This, in turn, allowed for the nutrients from the food to be released and used by the body much more quickly.

Warm Bloodedness

The Limbs

Breathing

Insulation

This article is currently being developed as part of a student project for an Anthropology course at the University of Colorado at Boulder. If you are not involved with this project, please do not further develop this article until otherwise noted. Thank you.