#dinocember2020

[rperboni]

(Note: I am not a professional paleontologist or even biologist. I am just and amateur paleoartist and enthusiast. If my infos are off in some way, feel free to correct them ^^)

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DINOCEMBER

3 -  Zuul crurivastator (tribute to Zuul, the Gatekeeper of Gozer, from the Ghostbusters franchise; "crurivastator" comes from the Latin "shank destroyer") - Late Cretaceous (75 Ma BCE) - Judith River Formation, Montana, US Formally named in 2017, Zuul is one of the most fantastic findings of recent years, being the most complete ankylosaur fossil in North America, preserving about 99% of the 6 meters-long animal's skeleton, as well as impressions of skin and the keratinous cover of its osteoderms in their life position, as well as his skull, which earned him his name, and the heavy bony club of the bridge of his tail, which earned him the nickname "Destroyer of Shins", based on what is believed to be the form of defense of this animal when using the club on its predators. The Judith River Formation, like many others rich in fossil extract, represents a coastal plain on the west bank of the Western Interior Seaway, which divided North America during the Cretaceous into two continental masses, Laramidia and Appalachia. In addition to Zuul, several hadrosaurs and ceratopsians are present in the region, as well as tyrannosaurs, raptors and crocodylomorphs, including the immense Deinosuchus, one of the largest that has ever existed. Ankylosaurs like Zuul were large plant-eaters that inhabited the Northern Hemisphere during the Cretaceous, being more dominant in certain regions of Asia, where they were apparently the main herbivores, while hadrosaurs dominated North America, being herbivores that ate plants closer to the ground, like bushes, small cycads and ferns, often being considered frugivorous, since the flowering plants and fruits started to appear near the end of the Cretaceous, which was something I decided to portray here, not excluding the possibility of some fruits having a hallucinogenic effect and affecting the hungry dinosaur, similarly to what happens with elephants when they feed on the fruits of the amarula, which naturally ferment when they fall from the tree, causing a drunken state in the animal.

- Color scheme based on a Giant Eland (Taurotragus derbianus)

[rperboni]

(Note: I am not a professional paleontologist or even biologist. I am just and amateur paleoartist and enthusiast. If my infos are off in some way, feel free to correct them ^^)

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DINOCEMBER

16 -  Oxalaia quilombensis (referencing the african deity Oxalá and the Brazilian quilombo settlements) - Late Cretaceous (100-93 Ma BCE) - Alcântara Formation, Maranhão, Brazil The largest non-avian theropod found in Brazil, Oxalaia is a large spinosauridae that lived in a region of tropical forests cut by rivers and lagoons, dominated by conifers, horsetails and ferns, surrounded by a vast semi-arid region, almost like an oasis in the middle of a merciless desert, where this animal reigned over the others, like a true river dragon in the middle of Cajual Island, where it had been discovered. Formally named in 2011, this theropod was described by Alexander Kellner, Elaine Machado, Sergio Azevedo, Deise Henriques, and Luciana Carvalho, based on the fossil of the tip of its snout, unique enough to be a new species, estimated to be between 12 and 14 meters long and weighing up to 7 tons. The similarities between Oxalaia and its most famous relative, the Spinosaurus, found in Egypt and Morocco, go beyond its large dimensions and ecological niche, both being considered by some paleontologists as members of the same genus. With such a thought, and even considering Oxalaia as a very close relative and distinct from its African counterpart, the new discoveries related to Spinosaurus could be applied to the Brazilian dinosaur, such as the various adaptations for a semi-aquatic life, as shorter posterior members, nostrils on top of the head, conical teeth for catching slippery prey and, more recently discovered, long neural spines on its tail, similar to that of a newt, which would assist in underwater locomotion. In addition, much of the paleofauna present in the Alcântara Formation is very similar to the Kem Kem and Bahariya formations in North Africa, such as truly gigantic fish, sauropods, pterosaurs, noasauridae and crocodylomorphs, in addition to the famous theropod Carcharodontosaurus, present as a "adversary" of both Oxalaia and Spinosaurus on both continents.

- Color based on three different animals: Cuvier’s dwarf caiman (Paleosuchus palpebrosus), Cryptic Golden Tegu (Tupinambis cryptus) and Paraguayan Caiman Lizard (Dracaena paraguayensis).

[rperboni]

(Note: I am not a professional paleontologist or even biologist. I am just and amateur paleoartist and enthusiast. If my infos are off in some way, feel free to correct them ^^)

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DINOCEMBER

5 -  Pachycephalosaurus wyomingensis (From Greek “Thick-headed lizard”) - Late Cretaceous (70-66 Ma BCE) - Hell Creek, East Coat, USA

One of the most iconic North American dinosaurs, the Pachycephalosaurus was a bipedal animal, being the largest member of its group, about 4.5 meters long and weighing 450 kg. Its most striking feature is certainly the bony dome at the top of its skull, about 25 cm thick, probably being used in disputes between males for partners, territory or simply for interaction between members of the species, but probably not in a similar way to current mountain goat, but more like a rhino , pushing each other with the head, or attacking the side of the body, more or less like a giraffe. Pachycephalosauridae were mostly present in the Northern Hemisphere during the Cretaceous, being among the last groups of non-Avian dinosaurs before the Cretaceous-Paleogene Extinction, 66 Ma ago. Probably the pachycephalosaurus had a good vision, with the orbits facing almost forward in its skull, which would have helped to locate the various predators with which it shared the Hell Creek environment, marked by coniferous and fern forests  and flooded plains, at the mercy of tyrannosaurs and raptors. The pachycephalosaurus diet should be mostly herbivorous, but its small, ridged teeth could very well capture insects and even steal eggs from other animals. Two other species of pachycephalosaurs in Hell Creek, Stygimoloch and Dracorex, are interpreted by many as growth stages of this animal, with Dracorex being an "adolescent" stage, both having less domed skulls and more spines on the sides of the head - in this drawing , Dracorex is the individual stealing an egg, possibly from a thescelosaurus, here taken as a youngling observed by an adult male.

- Color scheme based on an Ocellated Turkey (Meleagris ocellata)

[rperboni]

(Note: I am not a professional paleontologist or even biologist. I am just and amateur paleoartist and enthusiast. If my infos are off in some way, feel free to correct them ^^)

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DINOCEMBER

12 - Giraffatitan brancai (from Greek "titanic giraffe") - Late Jurassic (150-145 Ma BCE) - Tendaguru Formation, Lindi, Tanzania One of the most impressive sauropods that has ever existed, the Giraffatitan is the member of its family with the most complete fossil material, being for a long time considered the largest terrestrial animal that has ever existed, at least 26 meters long, 12 meters high and weighing somewhere between 15 and 60 tonnes, today being smaller than its distant relatives, the titanosaurs, but still impressive nonetheless. Although its name is not familiar to many, the Giraffatitan has long been considered the African species of the Brachiosaurus genus in North America, until recent research has indicated its identity as a species of its own, but still a member of the same family. As a brachiosauridae, the Giraffatitan had as main characteristics its forelimbs larger than its hindqlimbs, a relatively short tail for a sauropod and a long and at the same time muscular neck, which it would use to reach the highest leaves of trees such as conifers, araucaria and palm trees, being a high-browser, just like the current giraffes, probably walking in small groups through the large savanna of the Tendaguru Formation, next to a large coastal plain, dotted with areas of tropical vegetation and wetlands, but still without plants with flowers or fruits , having as "sister" formations, both in fauna and environment, the Morrison Formation, in the western USA, and the Lourinhã Formation, in Portugal, all showing the great abundance of Jurassic paleofauna. For a long time, these large sauropods were believed to be aquatic animals, unable to support their massive bodies on land and using their nostrils on top of their heads as a "snorkel", but everything indicates that both the Giraffatitan and other large sauropods were totally able to live on dry land, with relatively light bones and air sac systems to reduce their weight, albeit massive. The position of their nostrils was also revealed to be erroneous, having them closer to the tip of their snouts, which is the rule in most tetrapods.

- Color scheme based on a Nyala (Tragelaphus angasii)

[rperboni]

(Note: I am not a professional paleontologist or even biologist. I am just and amateur paleoartist and enthusiast. If my infos are off in some way, feel free to correct them ^^)

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DINOCEMBER

7 - Halszkaraptor escullei (from Latin "Halszka's hunter" in honor of the Polish paleontologist Halszka Osmólska) - Late Cretaceous (75-71 Ma BCE) - Djadochta Formation, Ömnögovi, Mongolia

Formally named in 2017, the Halszkaraptor is one of the great discoveries of the 2010s among non-avian dinosaurs, being the second of these animals with definitive proof of a semi-aquatic lifestyle - the first being the Spinosaurus in 2014. Approximate size of a mallard duck, this little dromaeosaur - or "raptor" - inhabited a region of streams and ponds in the middle of the seasonal semi-arid Djadochta formation, or "Flaming Hills" in the Mongolian language, presenting a series of characteristics that indicate such adaptations , with a center of gravity closer to the front of the body, which facilitates swimming and diving movements, in addition to a very long neck in relation to the size of the body and a more upright posture than that of others in its clade, in addition to from possibly having complex nerve endings in its snout to detect prey, more or less like a platypus. Cau et al. (2017) suggests that the Halszkaraptor would live similarly to the current mergansers, especially the analogy between the long neck and short body, in addition to the bird's serrated beak compared to the dinosaur's conical teeth, curved backwards to catch the slippery prey. The authors of the discovery also point to a swimming mode more similar to that of penguins than to ducks and grebes, using the short forelimbs as the main form of propulsion. There is a small error that I noticed only after finishing this drawing: Halszkaraptor's nostrils are located on the front of the beak, not close to the eyes like a duck. Sorry about that .

- Color scheme based on a Fishing Cat (Prionailurus viverrinus) and a Muscovy Duck (Cairina moschata)

[rperboni]

(Note: I am not a professional paleontologist or even biologist. I am just and amateur paleoartist and enthusiast. If my infos are off in some way, feel free to correct them ^^)

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DINOCEMBER

17 - Buriolestes schultzi (from Greek "Buriol's robber") 18 - Staurikosaurus pricei (from Greek "Southern Cross lizard") - Late Triassic (233 Ma BCE) - Santa Maria Formation, Rio Grande do Sul One of the great discoveries of 2016, the Buriolestes is a sauropodomorph, the lineage of non-avian dinosaurs characterized by their relatively rounded bodies, front legs with clawed first fingers and relatively long tails and necks, which over millions of years would be slowly replaced by the immense sauropods as the main herbivores in various environments around the world. However, unlike the most famous Plateosaurus and Musaurus, Buriolestes had sharp, serrated teeth, better adapted to a carnivorous and possibly omnivorous diet, unlike the leaf-shaped teeth of their herbivorous relatives. Such a characteristic would indicate that, initially on their evolutionary path, the Saurischians and probably the dinosaurs as a whole were all carnivores, gradually replacing the other animals that dominated several niches until the End-Triassic mass extinction circa 201 Ma BCE, after which the dinosaurs became the lords of the world. Amidst the sparse dry forests cut by rivers of the Santa Maria Formation, the Buriolestes would probably come into direct confrontation with the Staurikosaurus, a medium-sized herrerasauridae, about 2 meters long and 80 kg, being the first dinosaur described in Brazilian territory by American Edwin Harris Colbert, at the service of the American Museum of Natural History, where the fossil remains to this day. Competing with its most massive relative, the Gnathovorax, and the immense rauisuchian Prestosuchus, Staurikosaurus, like other herrerasauridae, was an active and opportunistic predator, feeding mainly on small animals, such as rhynchosaurs, lagerpetids and proto-mammals. The relationship between herrerasauridae and other dinosaurs is still nebulous, classically considered as distant cousins of the theropods or, in a more recent classification, as a sister group of sauropodomorphs within Saurischia, with theropods and ornithischians together in a separate group, called Ornithoscelida (Baron et al, 2017).

- Color schemes based on a Bush Dog (Speothos venaticus) for the Buriolestes and a Maned Wolf (Chrysocyon brachyurus) and Jaguarundi (Herpailurus yagouaroundi) for the Staurikosaurus. Pose inspired by the famous “Leaping Laelaps” by Charles R Knight.

[rperboni]

(Note: I am not a professional paleontologist or even biologist. I am just and amateur paleoartist and enthusiast. If my infos are off in some way, feel free to correct them ^^)

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DINOCEMBER

14 (Front) - Santanaraptor placidus (from the Latin "Thief of Santana") 15 (Back) - Aratasaurus museunacionali (combination of Tupi "ara" and "atá" and Greek "sauros" as "lizard born from fire") - Early Cretaceous (112-108 Ma BCE) - Romulado Formation, Ceara, Brazil Probably one of the most famous Brazilian dinosaurs, the Santanaraptor is a member of the tyrannosauroid family, presenting more basal characteristics similar to the Asian Guanlong and Dilong, with long legs adapted for running, a trait common to most theropods of this lineage at the beginning of their walk to become massive predators, in the future using their powerful skulls and jaws as their main hunting weapon. The original Santanaraptor fossil, formally named in 1996, mainly featured the animal's back and legs, as well as soft tissue prints, such as muscle fibers and parts of the epidermis, with an estimated size for an adult individual at just under 2 meters, close the size of a velociraptor. Also present on the great coastal plain at the same time as the Santanaraptor, the Aratasaurus was formally named in 2020, with its specific name honoring the National Museum of Brazil, unfortunately destroyed by the flames in 2018 resulting from years of neglect. The classification of Aratasaurus is still unclear, but it seems that it would also be a Coelurosaur, as well as Santanaraptor, part of the lineage that include birds and the most famous theropods, such as dromaeosaurs, tyrannosaurs and ornithomimosaurs. Aratasaurus seems to be more robust than Santanaraptor, about 3 meters long. I imagine that the two species would encouter themselves in life, like Aratasaurus perhaps acting similarly to a large spotted hyena while the agile Santanaraptor would be something like a coati or a mongoose, more of a opportunistic hunter.

- Color schemes based on a Northern Ground Hornbill (Bucorvus abyssinicus) for the Aratasaurus and a Madagascan Serpent Eagle (Eutriorchis astur) for the Santanaraptor.

[rperboni]

(Note: I am not a professional paleontologist or even biologist. I am just and amateur paleoartist and enthusiast. If my infos are off in some way, feel free to correct them ^^)

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DINOCEMBER

11 - Ubirajara jubatus (from Tupi “lord of the spears”) - Early Cretaceous (110 Ma BCE) - Crato Formation, Ceará, Brazil Named at the end of 2020, Ubirajara is one of the most impressive fossils found in Brazilian territory, being a member of the  Compsognathidae, small theropods covered with proto-feathers - or "dino-fuzz" - related to raptors and tyrannosaurs, whose most famous members are China's Sinosauropteryx and Germany's Compsognathus itself. Described from a partial skeleton without the skull, Ubirajara presents impressions of its fuzz, having an apparent "mane" in its dorsal region and pairs of quills on its shoulders, similar to what is found in the current birds-of-paradise, probably used in courtship or to intimidate rivals. The Crato Formation, as well as most of the formations in the Araripe Basin, would be the margins of a large saltwater lagoon, as well as a system of rivers surrounded by gymnosperms and some of the first flowering plants, being rich in fossil extract, especially of pterosaurs, and some curious animals, like the Enantiornithe Cratoavis. Unfortunately, Ubirajara, like other Brazilian fossils, is a target of international fossil trafficking, not having a single native author in the paper that describes it, with the team led by David Martill, a German paleontologist who smugled the Ubirajara fossil to Germany in 1995, and he cannot set foot on Brazilian territory for this and other crimes. Since its description, Ubirajara has been the target of campaigns for its repatriation, as well as other national fossils. I use this drawing as my collaboration for the campaign, and that so that this colonialist and criminal mentality ceases to exist in the paleontological community.

- Ubirajara’s color scheme inspired by a Vinaceous-breasted Amazon (Amazona vinacea) and a Vulturine Parrot (Pyrilia vulturina) and Cratoavis’ colors isnpired by a Black-thorated trogon (Trogon rufus). All of them are Brazilian birds