Prehistoric: Therapsid & Gorgonopsia

Kingdom: Animalia - Phylum: Chordata - Class: Synapsida - Order: Therapsida - Suborder: Gorgonospia.
Over 29 species and 3 subfamily species known. - 25 Genera and 41 species.

Once known as "mammal-like reptiles" with little record. They are a suborder of theriodonts (major group that included ancestors of mammals. In the same period of time (Mid Permian) also lived another reptile-like therapsid. Gorgonopsians were small (no bigger than a large dog). They became apex predators due to the extinction of dinocephalians. Almost a complete fossil of Rubidgea (that had very large canines) was found in South Africa. Gorgonopsians are along with two other theriodonts (therocephalians and cynodonts). Theriodonts are related to Anomodontia (herbivorous) and Gorgonopsia include three subfamilies: Inostrancevillnae, Rubbifeinae, Gorgonopsinae.

The mammalian specializations are seen in their temporal fenestra (opening in the skull and obit), different tooth shape (heterodont), vaulted palate (situated at the back of nasal fossae; which some say is how they breathed when holding prey in their mouth, unlike reptiles). They also had incipiently developed ear bones. The lower jaws in reptiles have multiple bones, but in were diminished and became one full jaw bone. they had cheek-like bones. Their ribs also changed as well. The lumbar ribs have reduced. Ribcages that continue from the front to the back legs (this lost effectively divides the trunk and allows for a diaphragm (allows animals to breathe more effectively). Unlike reptiles, which have three eyes, the third "eye" was capable of seeing light and dark but is used to regulate body temperature. Cynodonts lost this third eye, due to being warm-blooded. Because endothermic animals have such a higher metabolism than reptiles, it needs more energy. Thus, they need to consume more food. Not thought to have full pelage (origin of fur and feather selective factors), but scales or bristles are unknown. They might have had both, like some mammals today still have. Petrified feces found that some Cynodonts had started to grow hair. suggested to been terrestrial and had morphology and bone microanatomy. Their legs were still splayed out (like reptiles) but not as sprawling as reptiles and plantigrade (meaning they walked on their "whole" foot). The legs could hold up the body better and higher than reptiles and also had forward orientation of the feet let them walk more like a mammal than reptiles. The Smilodon (Americas in the Pleistocene epoch (2.5 million years ago), Thylacosmilus (South America, Late Miocene-Pliocene epochs) and other prehistoric (and mammals even today, exp: Water deer (Hydropotes inermis) have long canine teeth (also known as saber), are the later ones to have this, but cynodonts (dog teeth) (clade Cynodontia) which are therapsids were the first to have these (260mya) and were the ancestor to modern mammals. Thus, teeth forms (canine, incisors, premolars, molars) these were found by cynodonts.

- Two Gorgonops -
- Dinogorgon (Dy-noe-go-gon) (Terrible gorgon) classification: Chordata, Synapsida, Therapsida, Gorgonopsia, was about 6.6 ft (1.8m) in length, skulls were 32 cm or 12 in. and 2m long (depending on species. D. quinquemolaris is the largest known species beyond 2 meters, D. pricei was around under 2 meters). Smaller than the largest gorgonopsids, Inostrancevia. It lived 259.9-252.17 million years ago (Wuchiapingian-Changhsingian). It was an extinct genus of Rubifgenine gorgonopsians and was in the Rubidgeini tribe. Relative to Lycaenops.living in the Late Permian of South Africa and Tanzania. It preyed on small therapsids and reptiles. It was named by Robert Broom, 1936.

• Inostrancevia (In-oh-stran-ve-ah) could reach about 11.5 ft (3.5m) in length, skull was narrow and long about 24in (60cm), it had 4.7in (12cm) saber-like teeth (adapting to being carnivores). Species: I. latifrons, I. uralensis, and I. alexandri (Type, and was named after Aleksandr Inostrantsev, who Vladimir P. Amitsky -1992, named). The largest known of gorgonopsid and lived in the Wuchiapingian of the Permian (256-259mya) and found in Russia.

  - Subfamily -

• Clelandia (Cle-lan-de-nah) was the smallest (3.2 in (1m) body length 7.4in (19cm) long and skull was 8.2in (21cm)). Of the subfamily Rubidgeinae (which was the last of subfamilies and the end of the family Gorgonopsidae. They still had saber-like teeth but were reduced in size and conical, replacement was quick with relative to basal thorocephalians. Rubidegeines can be eminent by the blade-like parasphenoid bone an reduced the preparietal bone (the jugal bone, was expanded in rubidgeins. Unlike other gorgonopsians, in which the bone is narrow) and Rubidgeini (subfamily). Its bite force was strong, with a wider skull, which made room for larger jaw muscles. It lived in the Late Permian of Africa. It has a small sclerotic ring (only rubidgenine with preserved sclerotic ring), meaning it was diurnal (animal/plant behavior which is actvity in the day, with periods of sleep. Species: C. mahora, C. maximus, C. scheepersi, and C. rubidgei (type?) named by Robert Broom -1948. There is little known of this species.

Species and all:
Order Therapsida
SUBORDER GORGONOPSIA: Family Gorgonopsidae:Aelurosaurus, Aloposaurus, Arctognathus, Arctops, Broomisaurus, Cerdorhinus, Cyonosaurus, Eriphostoma, Kamagorgon, Lycaenops, "Njalila", Nochnitsa, Paragalerhinus, Smilesaurus, Suchogorgon, Viatkogorgon, "Gorgonops" dixeyi. Subfamily Gorgonopsinae: Gorgonops, Sauroctonus, Scylacops. Subfamily Inostranceviinae: Inostrancevia, Pravoslavlevia. Subfamily Rubidgeinae: Aelurognathus,Ruhuhucerberus,Sycosaurus, Tribe, Rubidgeini, Clelandina, Dinogorgon, Leontosaurus,Rubidgea.

These animals are mostly overlooked in the public eye, but they play a large part in the history of mammals. They were strong and powerful creatures, with strong necks and muscles. Because there are so many of them, it would take hours to read every species and differences, but all of them have early signs of mammals. These animals weren't "true" mammals or "true" reptiles, they were in between, like Hynes (not a dog, but not a cat, but in between).

Posted on April 4, 2019 10:27 PM by backyardcreature