Journeys in the Triassic

We have not been to the Triassic in a good long while, but today we shall venture back there. Herrerasaurids are some of the earliest theropods and, arguably, some of the least understood still. Often this is due to incomplete fossil finds, such as the animal that will be discussed this week. However, a good portion of the post-cranial skeleton of this dinosaur has been recovered in Brazil, of all the places in South America. Typically when we here "dinosaur" and "South America" in the same sentence we typically think of Argentina and Jose Bonaparte. However, Staurikosaurus pricei was named by Edwin Colbert, born in Iowa, and more renowned for having a hand in the discoveries of Ghost Ranch, New Mexico, a lot of systematics work, and his work in Antarctica, just to name a sliver of the things he accomplished during his 96 years of life. Colbert's name for this 225 million year old agile bipedal predator translates to "Southern Cross Lizard" with the specific epithet being in honor of Brazilian paleontologist Llewellyn Ivor Price, who had actually collected the fossil. The fossil, as stated, is made up of quite a good portion of the post-cranial skeleton as well as the mandible. Hindlimbs, the pelvic girdle, and the vertebral column are nearly complete; however, the feet and forelimbs, ribs and cranial elements other than the mandible are lacking. All told, animals have been named on far less and the bones present indicate a predator that, at about 66lbs (30kg), 31in (80cm) tall, and 7.4ft (2.3m) long, was about the weight of the average Labrador Retriever but just a tad taller (and obviously longer). The remains that have been discovered and the primitive age of this dinosaur, however, have led to some educated guesses pertaining to the make up of the missing skeletal elements. Chief amongst these are depictions of the hands and feet of Staurikosaurus as five fingered and toed basal appendages. The running speed of Staurikosaurus, despite the primitive foot and pelvic girdle, is considered to be fairly quick given the structure of the legs. The long tail consisting of approximately 40 caudal vertebrae would have aided the quick little dinosaur in maintaining its balance at its higher speeds.