#archovember2023

[confusedhadrosaur]

Day 13: Dorygnathus banthensis

[saritawolff]

#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.

Argentina during the Colloncuran age was rife with small critters and did not have a lot of large predators, making Kelenken the likely apex predator. While it probably couldn’t have taken down large adult ungulates like Astrapotherium and Theosodon, it may have been able to hunt typotherians like Hegetotherium, Interatherium, Protypotherium, and Pachyrukhos. Rodents would have been most often on the menu, as cavys were abundent here, as well as lizards and snakes such as Waincophis. Small sparassodonts like Patagosmilus and Cladosictis, would have been both competitors and prey. Only one other dinosaur has been found here so far, the owl Yarquen.

[imfluentinfangirlandgay]

I really really need to practice my paleoart so I'm gonna try Archovember. (List of day prompts by @saritawolff is under the cut!) Day 1 is your choice, so I chose the leggiest of boys, Terrestrisuchus gracilis! Ignore the goofy eye, its been a while since I tried traditional art and I got too excited to erase the sketch lines and smudged it ;-;

T. gracilis lived during the Upper Triassic period, and contrary to its rather dinosaur-like appearance, it is actually one of the earliest known crocodylomorphs! Some estimates have it at about 1 meter (3 ft) long. It had long, thin legs and a thin frame. Its head was long and slender- perfect for catching tasty bugs! There seems to still be discourse over if it was a quadruped, a biped, or a mix of both (think like hadrosaurs!).

[catella-ars]

Belatedly finished @saritawolff 's Archovember

https://saritawolff.tumblr.com/post/731715077418385409/whelp-weve-got-about-a-week-and-a-half-til

[saritawolff]

#Archovember Day 7 - Supersaurus vivianae

Living in Late Jurassic North America, the diplodocid Supersaurus vivianae was one of the largest and longest sauropods to ever exist. With larger specimens reaching 33–35 metres (108–115 ft) long and weighing an estimated 35–40 metric tons (39–44 short tons), it was matched only by the Late Cretaceous titanosaur Argentinosaurus.

As a diplodocid, Supersaurus would have used it’s long, peg-like teeth to strip food from branches and swallow it without chewing, instead relying on gastroliths (small stones) to break down plant material in its gizzard. Due to the high stress stripping branches would place on its teeth, diplodocids continuously replaced their teeth throughout their lives, usually in less than 35 days! Supersaurus could have had as many as 5 teeth developing per tooth socket.

Supersaurus, like other diplodocids, had a long, whiplike tail which tapered at the end. They could have snapped this tail like a bullwhip, generating a sonic boom. This could have been used in mating displays or to ward off predators.

Being the largest animals living at the time, there weren’t many, if any, predators in the Morrison Formation that could have preyed on adult Supersauruses. However, young Supersauruses would have had a multitude of large theropods to look out for, including Allosaurus, Saurophaganax, Ceratosaurus, Torvosaurus, and Marshosaurus. Supersaurus would have lived alongside a variety of other sauropods such as Haplocanthosaurus, Smitanosaurus, Amphicoelias, Apatosaurus, Brontosaurus, Diplodocus, Brachiosaurus, Camarasaurus, Dystrophaeus, and the rare Barosaurus. There were a lot of Ornithischians in this formation as well, though not as numerous and diverse as the sauropods. They included the early ornithopods Camptosaurus, Dryosaurus, Nanosaurus, and Uteodon, the stegosaurians Alcovasaurus, Hesperosaurus, and Stegosaurus, the ankylosaurians Gargoyleosaurus and Mymoorapelta, and the heterodontosaur Fruitadens.

[saritawolff]

#Archovember Day 16 - Shantungosaurus giganteus

While hadrosaurs tend to be perceived as horse or cow-size, there were some intimidatingly huge members of the family. As the largest hadrosaur discovered so far, Shantungosaurus giganteus could reach 15 metres (49 ft) to 16.6 metres (54 ft) long and weigh an estimated 13 metric tons (14 short tons) to 16 metric tons (18 short tons). It lived in Late Cretaceous China, and would have filled a niche typically filled by sauropods in its ecosystem. As these dinosaurs have been found in a mass grave, it’s likely they also traveled in large, formidable herds. Shantungosaurus also had very large nostril holes which were probably covered by flaps of skin that could have inflated to amplify its calls.

Shantungosaurus lived alongside other hadrosaurs like Laiyangosaurus, Tanius, and Tsintaosaurus, all quite large animals but still overshadowed by Shantungosaurus. It would have also lived alongside a diverse array of ceratopsians like Sinoceratops, Ischioceratops, Zhuchengceratops, and Micropachycephalosaurus, as well as the ankylosaur Pinacosaurus and the oviraptorosaur Anomalipes. So far, only one sauropod has been found in this area, Zhuchengtitan, the tallest animal in its ecosystem… beating Shantungosaurus by a neck. The apex predator of this region was the tyrannosaur Zhuchengtyrannus. However, it’s likely would not have been able to take on an adult Shantungosaurus, but could have picked off young or sick individuals that strayed from the herd.

[saritawolff]

#Archovember Day 8 - Zhejiangopterus linhaiensis

Azhdarchids are known as the largest flying animals of all time, the last great stand of the pterosaurs before . They contained mighty giants like Quetzalcoatlus and Hatzegopteryx, who ruled the skies of the Late Cretaceous. But not all azhdarchids were flying carnivorous giraffes. Some of them were downright tiny, while others reached a more modest, respectable size. Slightly larger than a female Pteranodon, Zhejiangopterus linhaiensis was one such “moderately large” azhdarchid.

Zhejiangopterus lived in Late Cretaceous China and is so far the most complete azhdarchid known, making it very influential to our understanding of this amazing family of pterosaurs. As several specimens have been uncovered, it was probably fairly common in the Tangshang Formation. It lacked the bony crest seen in many of their relatives, instead opting for a long, straight, graceful profile. Like other azhdarchids, Zhejiangopterus were likely terrestrial stalkers similar to storks and ground hornbills, only using their wings to escape predators or move to new hunting grounds.

Not many other animals have been found in the Tangshang Formation. Alongside Zhejiangopterus, there is only the avialan Yandangornis (whose eggs and chicks and perhaps even adults, if they could catch them, could have been prey for the pterosaur) and an unnamed therizinosauroid. However, living in Late Cretaceous China, it could have also come across the titanosaur Dongyangosaurus further South, and further inland: the ankylosaur Gobisaurus, the pachycephalosaurid Sinocephale, the ornithomimid Sinornithomimus, the carcharodontosaurid Shaochilong, and the mysterious theropod Chilantaisaurus. No doubt there were also plenty of lizards, snakes, mammals, amphibians, and small dinosaurs hiding in the coastal grasses, ready to be nabbed by the dragon of Zhejiang.

[confusedhadrosaur]

Day 11: Macrospondylus bollensis