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To: Ichneumon
 
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Mammal-Like Reptiles

As previously stated, a succession of transitional fossils exists that link reptiles (Class Reptilia) and mammals (Class Mammalia). These particular reptiles are classifie as Subclass Synapsida. Presently, this is the best example of th e transformation of one major higher taxon into another. The morphologic changes that took place are well documented by fossils, beginning with animals essentially 100% reptilian and resulting in animals essentially 100% mammalian. Therefore, I have chosen this as the example to summarize in more detail (Table 1, Fig. 1).  

    
 
 
 
M. Eyes =           ?       
   Nose =           ?    
   Teeth incisors = ?
 
 
 
K. Eyes =           ?       
   Nose =           pointy
   Teeth incisors = small
 
 
 
J. Eyes =           Medium
   Nose =           stubby    
   Teeth incisors = BIG
 
 
 
I. Eyes =           Medium
   Nose =           less stubby
   Teeth incisors = big
 
 
 
H. Eyes =           smaller
   Nose =           more blunt
   Teeth incisors = smaller
 
 
 
 
G. Eyes =           SMALL
   Nose =           Pointer
   Teeth incisors = Skinny
 
 
 
 
 
F. Eyes =           BIG
   Nose =           Blunt
   Teeth incisors = Thin
 
 
 
 
E. Eyes =           HUGE!
   Nose =           pointy, again
   Teeth incisors = Bigger
 
 
 
 
D. Eyes =           Smaller
   Nose =           Getting wider
   Teeth incisors = Bigger: two!
 
 
 
 
C. Eyes =           Huge, again!
   Nose =           broader
   Teeth incisors = very small
 
 
 
 
B. Eyes =           less huge
   Nose =           less broad
   Teeth incisors = ??
 
 
 
 
A. Eyes =           bigger again
   Nose =           rounded
   Teeth incisors = small
 

Skulls and jaws of synapsid reptiles and mammals; left column side view of skull; center column top view of skull; right column side view of lower jaw. Hylonomus modified from Carroll (1964, Figs. 2,6; 1968, Figs. 10-2, 10-5; note that Hylonomus is a protorothyrod, not a synapsid). Archaeothyris modified from Reisz (1972, Fig. 2). Haptodus modified from Currie (1977, Figs, 1a, 1b; 1979, Figs. 5a, 5b). Sphenacodo n modified from Romer & Price (1940, Fig. 4f), Allin (1975, p. 3, Fig. 16);note: Dimetrodon substituted for top view; modified from Romer & Price, 1940, pl. 10. Biarmosuchus modified from Ivakhnenko et al. (1997, pl. 65, Figs. 1a, 1B, 2); Alin & Hopson (1992; Fig. 28.4c); Sigogneau & Tchudinov (1972, Figs. 1, 15). Eoarctops modified from Broom (1932, Fig. 35a); Boonstra (1969, Fig. 18). Pristerognathus modified from Broom (1932, Figs 17a, b,c); Boonstra (1963, Fig. 5d). Procynosuchus modified from Allin & Hopson (1992, Fig. 28.4e); Hopson (1987, Fig. 5c); Brink (1963, Fig. 10a); Kemp (1979, Fig. 1); Allin (1975, p. 3, Fig. 14). Thrinaxodon modified from Allin & Hopson (1992, Fig. 28.4f);Parrington (1946, Fig. 1); Allin (1975, p. 3, Fig. 13). Probainognathus modified from Allin & Hopson (1992, Fig. 28.4g); Romer (1970, Fig. 1); Allin (1975, p. 3, Fig. 12). Morga nucodon modified from Kermack, Mussett, & Rigney (1981, Figs. 95, 99a; 1973, Fig. 7a); Allin (1975, p. 3, Fig. 11). Asioryctes modified from Carroll (1988, Fig. 20-3b). Abbreviations: ag = angular; ar = articular; cp = coronoid process; d = dentary; f = lateral temporal fenestra; j = jugal; mm = attachment site for mammalian jaw muscles; o = eye socket; po = post orbital; q = quadrate; rl = reflected lamina; sq = squamosal; ty = tympanic. .
 
 
 


 
Are you convinced yet?
 
Oscillating eye sizes,
head shapes that shift back and forth,
teeth that are large, then small, then large again.
 
Yeah; I believe this stuff!

(The chart is from The Fossil Record: Evolution or "Scientific Creation" by Clifford A. Cuffey. It is on part 5 of a multipart article. The beginning of the article is here.  )

There are some Evo's who think... "It effectively demolishes the entire creationist argument. Excellent reading!"

After seeing these pix; do you?

639 posted on 04/06/2006 5:57:15 AM PDT by Elsie (Heck is where people, who don't believe in Gosh, think they are not going....)
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To: Elsie
Nothing wrong with big teeth/little teeth once you understand that it's the DNA making the difference, and it has "on" and "off" switches.

I think you have a better argument focusing on those "on" and "off" switches. There has to have been some high order data processing going on to come up with that one.

645 posted on 04/06/2006 6:14:37 AM PDT by muawiyah (-)
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To: Elsie

Those aren't pics - they're drawings.


669 posted on 04/06/2006 6:39:50 AM PDT by mlc9852
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