Profile image
Story Views
Now:
Last Hour:
Last 24 Hours:
Total:

Trypanognathus: the most primitive fingers and toes in the LRT

% of readers think this story is Fact. Add your two cents.

(Schoch and Voigt 2019 report on a new dvinosaur,
Trypanognathus (Fig. 1) preserving both cranial and post-cranial data down to a few tiny fingers and one preserved toe phalanx + four metatarsals). In the large reptile tree (LRT, 1441 taxa, subset Fig. 2).

Figure 1. Trypanognathus in situ, colorized to bring out ribs and limbs. ” data-medium-file=”https://pterosaurheresies.files.wordpress.com/2019/04/trypanognathus-overall588.gif?w=584&h=1509?w=116″ data-large-file=”https://pterosaurheresies.files.wordpress.com/2019/04/trypanognathus-overall588.gif?w=584&h=1509?w=396″ class=”size-full wp-image-36514″ src=”https://pterosaurheresies.files.wordpress.com/2019/04/trypanognathus-overall588.gif?w=584&h=1509″ alt=”Figure 1. Trypanognathus in situ, colorized to bring out ribs and limbs. ” width=”584″ height=”1509″ />

Figure 1. Trypanognathus in situ, colorized to bring out ribs and limbs. Note the flat long body, flat wide head and small limbs. These are primitive traits shared with Panderichthys and Tiktaalik.

According to Schoch and Voigt 2019:
“The skull closely resembles that of the early Permian dvinosaurian genus Trimerorhachis in outline and suture topology, but the occiput and the palate differ substantially. Derived states are the penetration of vomerine tusks through the splenial and symphyseal
tusks through the premaxilla. Trypanognathus shares with dvinosauroids the lack of a squamosal embayment, an elongated basipterygoid process, a foreshortened palatine ramus exclusively reaching the ectopterygoid, the absence of pterygoid denticles, and enlarged palatal tusks. The body is elongate with well-ossified, but small limbs, the presacral count is circa 28, and the pleurocentra are large and reached ventrally almost as far as the intercentrum.”

Schoch and Voight nested dvinosaurs as derived taxa,
more derived than the basal lepospondyls, Neldasaurus, and Trimerorhachis, just the opposite of the LRT, which nests dvinosaurs as the most basal tetrapods with fingers and toes, instead of fins. Note the flat long body, flat wide head and small limbs. These are primitive traits shared with Panderichthys and Tiktaalik two taxa without fingers and toes.

Figure 2. Subset of the LRT focusing on the basal tetrapods including Trypanognathus. ” data-medium-file=”https://pterosaurheresies.files.wordpress.com/2019/04/basaltetrapods588.jpg?w=584&h=416?w=300″ data-large-file=”https://pterosaurheresies.files.wordpress.com/2019/04/basaltetrapods588.jpg?w=584&h=416?w=584″ class=”size-full wp-image-36515″ src=”https://pterosaurheresies.files.wordpress.com/2019/04/basaltetrapods588.jpg?w=584&h=416″ alt=”Figure 2. Subset of the LRT focusing on the basal tetrapods including Trypanognathus.” width=”584″ height=”416″ srcset=”https://pterosaurheresies.files.wordpress.com/2019/04/basaltetrapods588.jpg?w=584&h=416 584w, https://pterosaurheresies.files.wordpress.com/2019/04/basaltetrapods588.jpg?w=150&h=107 150w, https://pterosaurheresies.files.wordpress.com/2019/04/basaltetrapods588.jpg?w=300&h=214 300w, https://pterosaurheresies.files.wordpress.com/2019/04/basaltetrapods588.jpg 588w” sizes=”(max-width: 584px) 100vw, 584px” />

Figure 2. Subset of the LRT focusing on the basal tetrapods including Trypanognathus.

It is traditional to consider Dvinosauria
as derived taxa within the clade Temnospondyli. Here in the LRT, after testing a wide gamut of basal tetrapods, the Dvinosauria is a basal clade/grade leading to all higher limbed tetrapods, including the clade Temnospondyli and Lepospondyli, and ultimately Reptilomorpha. The retention of robust gill bars along with primitive hands and feet are signs of their primitive status.


References
Schoch RR and Voigt S 2019. A dvinosaurian temnospondyl from the Carboniferous-Permian boundary of Germany sheds light on dvinosaurian phylogeny and distribution. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2019.1577874.



Source: https://pterosaurheresies.wordpress.com/2019/04/21/trypanognathus-the-most-primitive-fingers-and-toes-in-the-lrt/

Support BeforeitsNews by trying our natural health products! Join our affiliate program

APeX - Far superior to colloidal silver in destroying viruses, bacteria and other pathogens.
Ultimate Curcumin - Natural pain relief, reduce inflammation and so much more.
Supreme Fulvic - Nature's most important supplement! Vivid Dreams again!  See Testimonials
MitoCopper - First bioavailable copper destroys pathogens and gives you more energy.
Prodovite - The Secret To Healing is in the Blood! Complete absorption in 5 minutes.

Report abuse

    Comments

    Your Comments
    Question   Razz  Sad   Evil  Exclaim  Smile  Redface  Biggrin  Surprised  Eek   Confused   Cool  LOL   Mad   Twisted  Rolleyes   Wink  Idea  Arrow  Neutral  Cry   Mr. Green

    SignUp

    Login

    Newsletter

    Email this story
    Email this story

    If you really want to ban this commenter, please write down the reason:

    If you really want to disable all recommended stories, click on OK button. After that, you will be redirect to your options page.