Permian/Triassic Age Reptiles and Amphibians

http://www.reptileevolution.com/cephalerpeton.htm

MISSING LINK

http://macroevolution.narod.ru/_pamphibia.htm

Before the Dinosaurs, reptiles evolved into three main lineages.

First were the Parareptiles. Parareptiles showed primitive features and would eventually have the turtles as its decendants.

Therapsids showed many mammal like characteristics and would eventually evolve into the Mammals.

Archosaurs included the thecodonts and would eventually evolve into the Dinosaurs, crocodilians and birds.

The Permian age was named for the Perm region in Russia which was famous for its fossils of that age. Other well known localities famous for their Permian faunas are South Africa and Texas and New Mexico.

Museum of Arts and Sciences, Daytona Beach, Floridathe Russian National Collection

Garjania3.jpg Garjainia triplocostata240 myaRassypnayaOrenburg RegionRussia

Garjainia was a Thecodont, an early representative of the Archisaurs, the group that eventually included the Dinosaurs and Crocodilians and replaced the Therapsids(mammal-like reptiles).

Titanophoneus potens.JPG

Titanophoneus.jpg Titanophoneuspotens 260-265 myaIsheevoTatarstan

Titanophoneus, a therapsid was the top predator of its time.

biarmosuchus.JPG

Biarmosuchus.jpg Biarmosuchus tener260-265 myaOcherPermRussia Type specimen

Biarmosuchus, the size of a large dog, was a primitive predatory therapsid.

Inostranseveria.jpg Inostranceviaalexandri250-255 myaMalaya SeveriaArkangesk Reg.North RussiaType Specimen

Inostrancevia was a large sabre-toothed gorganopsid predator that had a more upright stance than earlier therapsids.

Estemmenosuchus.jpg Estemmenosuchusuralensis 255 myaOcherPermRussia

Estemmenosuchus was a large plant eating Therapsid (Mammal-like reptile) characterised by large bumps or horns on its skull and a somewhat sprawling posture.

Estremmenosuchus.jpg

Rhabdiodromus.jpg Rhadiodromusklimova 230-235 myaBerdyanka

Orenburg regionRussia

Rhadiodromus was a large tusked mammal-like reptile of the early Triassic.

Lystrosaurus.jpg Lystrosaurus georgi240 myaAtashihka NizhegorodskayaRussia

Lystrosaurus appeared very early in the Triassic and spread very widely. Examples have been found from Russia, India, Africa, to Antarctica. A plant-eating therapsid, Lystrosaurus had large feet, useful in swampy areas..

Scutosaurus.jpg Scutosaurus karpinski250-255 myaSokolkiArkangelskRussia

Scutosaurus, a very large barrel chested aquatic parareptile, is part of the lineage that eventually gave rise to Turtles.

Scutosaurus2.jpgScutosaurus karpinski250-255 myaSokolkiArkangelskRussia

Lanthosuchus.jpg (L) Lanthosuchus warsoni260-255 myaIsheevo, Tatarstan

(R) Deltavjatia viatkensis250-255 myaPerm Region,

Lanthosuchus was an aquatic parareptile with an extremely flattened skull. Deltavjatia was a terrestrial parareptile showing many turtle like features, particularly in its skull

Parotosuchus.JPG

paratosuchus 2. http://macroevolution.narod.ru/_pamphibia.htm

Paratosuchus.jpg Parotosuchusorenburgensis235-245 myaOrenburg regionSouth Russiaamphibian

Parotosuchus was an amphibian with a flattened skull and armored skin..

img005.jpg http://faculty.evansville.edu/de3/b39902/PPoint/PermioTriassic/sld005.htm

Theriodonts http://faculty.evansville.edu/de3/b39902/PPoint/PermioTriassic/sld005.htmhttp://en.wikipedia.org/wiki/TheriodontTheriodonts ("Beast Tooth", referring to more mammal-like teeth), are the third main group of therapsids. They can be defined in traditional, Linnaean terms, in which case they are a suborder of mammal-like reptiles that lived from the Middle Permian to the Middle Cretaceous, or in Cladistic terms, in which case they include not only the traditional theriodonts but also their descendants the mammals as well (in the same way that, cladistically speaking, the theropod dinosaurs include the birds as a sub-clade).

Theriodonts appeared almost the same time as the anomodonts, about 265 million years ago, in the Middle Permian. Even these early theriodonts were more mammal-like than their Anomodont and Dinocephalian contemporaries.

anomodonts.JPG

260-Million-Year-Old Therapsid.JPG

Tiarajudens eccentricus is a newly described genus and species of herbivorous saber-toothed anomodonts.Tiarajudens is an herbivorous synapsid with saber-teeth

These teeth were probably used to scare off predators and intimidate them instead of using them for offense or defense. These teeth would have little use on grinding up plants.Paleontologists are certain that this was an herbivorous animal because of the surrounding teeth around the gigantic canines - flat, grinding teeth.It had a heterodont dentition, all of its teeth were different. Actually, this is a common character in the class of Mammalia, the descendants of hairy synapsids. Although, this is the earliest therapsid to have heterodont teeth. It lived in the Middle Permian, ~260 ma, about 200 million years before the second earliest known therapsid to have heterodont teeth.Tiarajudens was found in southernmost Brazil, in what is now Rio Grande do Sul. This therapsid is known from one specimen, its holotype, called UFRGS PV393P, a complete skull.Tiarajudens was described by Juan Carlos Cisneros, Fernando Abdala, Bruce S. Rubidge, Paula Camboim Dentzien-Dias, Ana de Oliveira Bueno in 2011. "Tiaraju" is latin for "Tiarajú" while "dens" is latin for "tooth". The special name, eccentricus, is Latin for

"eccentric," due to its bizarre appearance.Abstract - Anomodonts, a group of herbivorous therapsid “mammal-like reptiles,” were the most abundant tetrapods of the Permian. We present a basal anomodont from South America, a new taxon that has transversally expanded palatal teeth and long saber canines. The function of the saber teeth is unknown, but probable uses include deterring attack from predators and intraspecific display or combat. The complex palatal teeth were used to process high-fiber food and represent early evidence of dental occlusion in a therapsid. This discovery provides new insight into the evolution of heterogeneous dentition in therapsids and broadens our understanding of ecological interactions at the end of the Paleozoic. Reference - Cisneros, J.C.; Abdala, F.; Rubidge, B.S.; Dentzien-Dias, D.; Bueno, A.O. (2011). "Dental Occlusion in a 260-Million-Year-Old Therapsid with Saber Canines from the Permian of Brazil". Science 331: 1603-1605.

http://www.sciencemag.org/content/331/6024/1525.summary

http://www.sciencemag.org/content/331/6024/1525.figures-only

http://www.sciencemag.org/content/331/6024/1603.figures-only

Fig. 1 Cranium and dentition of T. eccentricus from the Permian of Brazil (UFRGS PV393P, holotype). (A) Photograph and (B) drawing of the skull in lateral view. (C) Photograph and (D) drawing of the skull in medial view (parasagittal section). (E) Saber canine in basal cross section; anterior is to the left. (F) Incisiforms in lingual view (iii to v indicate tooth positions). (G) Palatal molariforms in occlusal view (stereophotograph). (H) Lateral view of palatal teeth, showing a posterior-to-anterior replacement sequence; replacement teeth are indicated by arrows. Scale bars, 50 mm for (A) to (D) and 10 mm for (E) to (H). Abbreviations: an, angular; ar, articular; c, canine; ect, ectopterygoid; j, jugal; la, lacrimal; lf, left frontal; ln, left nasal; lpm, left premaxilar; mx, maxilla; po, postorbital; pof, postfrontal; prf, prefrontal; pt, pterygoid; q, quadrate; qj, quadratojugal; rf, right frontal; rn, right nasal; rpm, right premaxilar; sa, surangular; sc, scleral ossicles; sm, septomaxilla; sq, squamosal; t, teeth.

Fig. 2 (A) Replacement palatal tooth in posterior view (last tooth in the row, apex to the top). (B and C) Reconstruction of fourth palatal tooth, (B), posterior, slightly medial view, (C), occlusal view. (D) and (E) Comparative figures showing a skull reconstruction of T. eccentricus (D) and the skull of the extant saber-toothed water deer Hydropotes sp. (E). Scale bar, 10 mm for (A) to (C). (D) and (E) are not to scale.

Fig. 3 Stratigraphically calibrated phylogeny of Permian basal anomodonts (5) and other therapsids. Circles represent taxa known from a single locality. Values represented above the branches are decay values; values below are from symmetric resampling. The temporal range of Dimetrodon extends to the earliest Permian (Asselian). Abbreviations: Ciste., Cistecephalus; Chang., Changhsingian; Eodicyno., Eodicynodon; K, Karoo Assemblage Zone; Kungu., Kungurian; Prist., Pristerognathus; PTB, Permo-Triassic Boundary; Road., Roadian; SGCS, Standard Global Chronostratigraphic Scale (27); Tropi., Tropidostoma; Wuchiaping., Wuchiapingian. Ages are in million years ago.

Dicynodont.jpg http://blogevolved.blogspot.com/2009/04/synapsids-in-art.html

DicynodontevolutionRay.jpg http://www.earthhistory.org.uk/transitional-fossils/reptile-to-mammal/

img006.jpg http://faculty.evansville.edu/de3/b39902/PPoint/PermioTriassic/sld005.htmhttp://en.wikipedia.org/wiki/DicynodontThe Dicynodontia are a taxon of Therapsids or mammal-like reptiles. Dicynodonts were small to large herbivorous animals with two tusks, hence their name, which means 'two dog tooth'. They are also the most successful and diverse of the non-mammalian therapsids, with over 70 genera known, varying from rat- to ox-sized.

Lycaenops The sabre-toothed Lycaenops was a top predator of the latest Permian in South Africa. Lycaenops was a gorgonopsian, one of a group of highly successful animals that dominated faunas in the Late Permian, but were wiped out, together with 90 per cent of all species, by the end-Permian mass extinction.Photo: Mike Benton / University of Bristol

http://www.thedailygreen.com/environmental-news/latest/extinction-recovery-47011901

http://www.ucmp.berkeley.edu/synapsids/gorgonopsia.html

Despite their agility and fearsome teeth, the Gorgonopsia went extinct by the end of

the Permian, along with most other synapsid groups.

Lycaenops : One of the best studied gorgonopsians is Lycaenops. You can see the mounted skeleton of this carnivore above

Notice that the legs are held close to the body as they are in mammals, and not out to either side as in reptiles. The animal was about one meter long.

Gorgo+skeleton.jpg http://blogevolved.blogspot.com/2009/04/synapsids-in-art.html

800px-Moschops.jpg http://blogevolved.blogspot.com/2009/04/synapsids-in-art.html

IMG_3256.jpg http://blogevolved.blogspot.com/2009/04/synapsids-in-art.html

Edaposaur.jpg http://blogevolved.blogspot.com/2009/04/synapsids-in-art.html

edaposaur+skull.jpg http://blogevolved.blogspot.com/2009/04/synapsids-in-art.html

IMG_3249.jpg http://blogevolved.blogspot.com/2009/04/synapsids-in-art.html

last pelycosaur.JPG