#archovember

Dinosaur Tianyuraptor ostromi, of Late Cretaceous, China!

Tianyuraptor ostromi is part of the Microraptoria clade, a clade of dromaeosaurs known for long feathers on both their legs and arms giving them “four wings”. However, Tianyuraptor had unusually short arms for a microraptorian, paired with unusually long lower hindlimbs. It was also larger than all other known microraptorines. Tianyuraptor was likely not doing any gliding, but was instead adapted as a ground-based pursuit predator.

Found in the Yixian Formation of Late Cretaceous China, Tianyuraptor ostromi would have lived alongside a plethora of other theropods, including other microraptorians like Sinornithosaurus and Zhongjianosaurus, compsognathids like Sinosauropteryx, a variety of avialans like Zhongornis, Yixianosaurus, Shanweiniao, Sapeornis, Longicrusavis, Hongshanornis, Iteravis, Dalingheornis, Archaeorhynchus, and Confuciusornis, oviraptorosaurs like Similicaudipteryx, therizinosaurs like Beipiaosaurus, and tyrannosauroids like Dilong. Tianyuraptor could have also met ankylosaurs like Liaoningosaurus, ceratopsians like Psittacosaurus lujiatunensis, and hadrosaurs like Jinzhousaurus. Pterosaurs also lived here, including ctenochasmatids like Cathayopterus and Elanodactylus, istiodactylids like Luchibang, and other pterodactyloids like Ningchengopterus.

#Archovember Day 19 - Kelenken guillermoi

The Phorusrhacids, commonly known as “terror birds” were the last dinosaurian apex predators to hunt on land. The largest known phorusrhacid, Kelenken guillermoi, lived in the Middle Miocene of Argentina. It is known only from a skull (though it is one of the most complete large phorusrhacid skulls) and a leg and toe bone, so the rest of its anatomy must be inferred from other phorusrhacids. The skull, the largest of any known bird, is 716 mm (2.3 ft) long, allowing us to estimate Kelenken’s height at around 3 m (9.8 ft) tall. Kelenken would have lived in an open, grassland environment. Its long, slender tarsometatarsus suggests that it was a fast runner, likely adapted for chasing down small animals like rodents, marsupials, and lizards. While large, its skull was relatively weak, so it would have had difficulty gripping onto and subduing large, struggling prey. Instead, it likely preyed on animals it could swallow whole and/or, if targetting larger prey, used repetitive, targeted pecks with its beak. It could have also used its feet to restrain prey. While only Kelenken’s phalanx toe bone has been found, other large phorusrhacids (as well as their living relatives, the seriemas) have a “sickle claw” on their second digits, similar to dromaeosaurs. These claws could have also been used to restrain prey, or to kick out and strike.

Archovember day eight! Euparkeria Capensis

little guys in a cave, i really hate this one its probably the worst one ive made. shouldnt have drawn in orange but im not redoing it

Belatedly finished @saritawolff 's Archovember