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David Marjanovic 3 April wrote:
1) "There has been the suggestion that
Diadectomorphs are
Synapsids".
Something of similar was suggested by Berman
et Al. on the basis of the otic trough, but Laurin & Reisz 1995 pointed that
even if it is present in Casea several early
Synapsids like Eothyris have not otic trough.
2) "You do know that by your suggestion you
are a reptile and reptilia became the same of
amniota".
I am a reptile as they are the turtles and the
birds, but Reptilia not became the same of Amniota, because Synapsids, Diapsids,
and Anapsids are united by advanced characters that well separated them from
Diadectomorphs (Laurin & Reisz 1995).
Only for example, using as a basis the phylogeny of
Laurin and Gauthier in Tree of Life and Changing some names this is the
result:
____________________________Diadectomorpha
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| ________________________Synapsida
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_Mesosaurid.
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| _____Miller.
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_Anapsida_| | _Acleist.
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| |
| _|
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| |
| | |_Lantha.
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|_| |
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| |
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Amniota_| |
| |_|
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| _Macro.
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| |
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| |_Nycti.
| | |
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|_Reptilia_|
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|_| _Par.
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| |_|
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|_Proc
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|_Sauropsida_|
|_? Test.
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__Captorhin.
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|_Romeriida_| _Protoroth
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|_Diapsida
3) "The situation in amniote phylogeny is so
solid".
I cannot agree with this statement, unless the
"solidity" is restricted to the fact that synapsids diverged before
sauropsids.
4) "It is better to abandon the term
reptilia".
The language and the terms are important, at least
at educative level, and the historical term Reptilia has acquired an high
semantic value that cannot easily dismissed, it recalls immediately amniotic
primitivity (although actual lizards and snakes are not primitive). After all
A.S. Romer himself in his "The vertebrate story- 1967" defined the amniotic egg
as the reptilian egg.
Steve Brusatte 3 April wrote:
"Everything I've read has stated what Dr. Holtz
posted back in 1995: that Dimetrodon (and other early synapsids) likely
had poor color vision (along with glandular skin etc.)
At the reliable site www.ucmp.berkeley.edu/synapsids/pelycosaurs.html
I have read the following:
"It is believed that pelycosaurs, like their living
mammal relatives, were endothermic, which means that they maintained a constant
internal body temperature. This is another characteristic that sets pelycosaurs
apart from reptiles".
It would be interesting to know who really believe
it and on which evidence. Perhaps the Dimetrodon sail? Maybe the sail favorites
the temperature control in an ectothermic body, but endothermy implicate high metabolic rate and is totally another
thing. Not to mention the other pelycosaurs that are completely without sail. It
is true that some pelycosaurs have slender limbs but the position is always
sprawling.
The educators are obliged to a
big straining to show the difference between a pelycosaur and a
reptile.
Alberto Arisi
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