Tag: ankylosauria
Retro vs Modern #03: Hylaeosaurus armatus
Despite being the third-ever scientifically named dinosaur genus, and being used in the first official definition of dinosaurs as a group, Hylaeosaurus armatus has ended up as a much less well-known name than Iguanodon or even Megalosaurus.
It was also the very first ankylosaur to be discovered, found as a partial skeleton in Southeast England in the early 1830s. Its large bony spikes were quickly recognized as being some sort of defensive armor, initially thought to be arranged in a vertical row along the animal's back and tail.
The Victorian Crystal Palace statue of Hylaeosaurus is surprisingly decent for such an early attempt at reconstructing something as weird as an ankylosaur. It gives the impression of a slower and much more lizard-like animal than Iguanodon or Megalosaurus, showing it as a large squat quadruped with hoof-like claws and heavily armored scaly skin, with long spines running along its back and numerous smaller bony bumps over its head and sides.
Discoveries of other more complete armored dinosaurs began to give a better picture of what ankylosaurs actually looked like. But although Hylaeosaurus was soon recognized as having had multiple rows of spikes rather than just one, actual reconstructions of it seem to have been scarce during this period – mostly all derivative of a single 1869 image that depicted it as a sort of fat sprawling pinecone-lizard bristling with spikes.
Still only known from fragmentary material, Hylaeosaurus has remained rather obscure for a long time. In the 21st century it's started to get a bit more attention, however, with the original specimen being further prepared and examined – and 2020 was Hylaeosaurus' big year, with both a redescription of the genus being published and it also being featured on a special-edition British 50p coin.
Hylaeosaurus was probably around 4m long (~13′), and lived in southeast England about 140-136 million years ago. It may have also ranged further across Europe, with possible remains known from Germany and some more dubious records from France, Spain, and Romania. Generally classified as an early nodosaurid, most of our modern knowledge of what it would have looked like comes from other discoveries of much better-known ankylosaurian relatives, including some exquisitely well-preserved examples in the last few years like Borealopelta and Zuul.
It would have had a low triangular head, with a toothless beak at the front of its jaws and leaf-shaped teeth further back, and a pair of short horns on the back of its skull behind its eyes. Rows of spiky osteoderm armor ran along is body, with longer curving spines over its shoulders, all covered in thick keratin sheaths that would have made them look even larger in life. Numerous smaller bony nodules in its skin filled in the gaps between the armor, forming a tough protective shield over its entire back. Its short powerful limbs had hoof-like claws, and if it was indeed a nodosaurid its tail would have lacked the famous club of its ankylosaurid cousins.
Based on Borealopelta we even now know a little bit about the potential coloration and patterning of these animals – some of them were reddish-colored, with a countershaded camouflage pattern, darker on top and lighter on the underside.
Author adminPosted on March 3, 2022 March 3, 2022 Categories paleoart, retro vs modern, science illustration, theme monthsTags ankylosaur, ankylosauria, dinosaur, hylaeosaurus, nodosaur, nodosauridae, ornithischia, retro vs modern, retrosaurs, thyreophoraLeave a comment on Retro vs Modern #03: Hylaeosaurus armatus
Stegouros
While some ankylosaurs are famous for their specialized tail clubs, Stegouros elengassen here had something else entirely going on with its rear end.
Known from the late Cretaceous of southern Chile, about 75-72 million years ago, this small ankylosaur was around 1.5m long (~5′), roughly the size of a large dog. It had a proportionally larger head and more slender limbs than most other ankylosaurs, and a pelvis more resembling a stegosaur, but its most distinctive feature was its tail – it had a completely unique never-before-seen type of tail weapon, with a flat "frond-like" structure formed from several pairs of large fused osteoderms making a shape resembling a macuahuitl.
It seems to have been part of a previously unrecognized very early-branching lineage of Gondwanan ankylosaurs – the parankylosaurians – with its closest relatives Antarctopelta and Kunbarrasaurus also included in this new group. And since the tail regions of both of those other species are poorly known, this means they may also have possessed macuahuitls.
Author adminPosted on December 13, 2021 December 13, 2021 Categories paleoart, science illustrationTags ankylosaur, ankylosauria, archosaur, dinosaur, macuahuitl, ornithischia, parankylosauria, stegouros, thyreophoraLeave a comment on Stegouros
Eons Roundup 9
New year, new PBS Eons commission roundup day!
Neotherium mirum
Valenictus sp.
The ancient walruses Neotherium and Valenictus, from "How the Walrus Got Its Tusks"
https://www.youtube.com/watch?v=BKDGYGV2LK8
Borealopelta markmitchelli (life restoration)
Borealopelta markmitchelli ("bloat-and-float" carcass)
The nodosaurid ankylosaur Borealopelta, in both alive and "bloat-and-float" carcass states, from "The Dinosaur Who Was Buried at Sea"
https://www.youtube.com/watch?v=a-UZXBF63z4
Gobisaurus domoculus
Dyoplosaurus acutosquameus
The ankylosaurid ankylosaurs Gobisaurus and Dyoplosaurus, from "How Ankylosaurs Got Their Clubs"
https://www.youtube.com/watch?v=lRt-4SdzWrk
Author adminPosted on January 4, 2021 September 13, 2021 Format GalleryCategories commissioned work, paleoart, science illustrationTags ankylosaur, ankylosauria, ankylosauridae, archosaur, bloat and float, borealopelta, carcass, carnivora, dinosaur, dyoplosaurus, eons roundup, gobisaurus, mammal, marine mammal, neotherium, nodosaur, nodosauridae, odobenidae, ornithischia, pbs eons, pinniped, pinnipedimorpha, seal, taphonomy, thyreophora, valenictus, walrusLeave a comment on Eons Roundup 9
Zuul crurivastator, an ankylosaur from the Late Cretaceous of Montana, USA (~75 mya).
One of the most complete ankylosaurids ever found in North America, it's known from a full skeleton about 6m long (20′). Much of its bony osteoderm armor is preserved in life position, along with skin impressions and the remains of keratinous scales and spike sheaths – although so far only the skull and tail have actually been fully prepared and described.
(The fuzz on this reconstruction is highly speculative, but since it'll likely end up inaccurate anyway once of the rest of the body is fully described… why not have some fun with it?)
Its genus name was inspired by its skull's resemblance to Zuul the Gatekeeper from the 1984 movie Ghostbusters, while its species name translates to "destroyer of shins" in reference to its especially large tail club.
Author adminPosted on October 9, 2017 August 8, 2022 Categories paleoart, science illustrationTags ankylosaur, ankylosauria, ankylosauridae, archosaur, dinosaur, inktober, ornithischia, thyreophora, zuulLeave a comment on Zuul
Unsolved Paleo Mysteries Month #16 – Strange Snoots 2: Oddball Ornithischians
Those extinct horses weren't the only ancient creatures with unexplained noses. Some dinosaurs had equally weird things going on with their snouts – and while hadrosaurs' big honkin' snoots are fairly well-known, there were other ornithischians with their own bizarre nasal anatomy.
Triceratops horridus skull and head reconstruction
Many ceratopsids had an enormous nasal opening forming a giant bony "window" through their snout, with the chasmosaurines like the famous Triceratops having additional bony projections and hollowed regions within these holes. They probably supported some huge elaborate cartilage structures in life, but what they were for is still a mystery. They may have helped with heat dissipation or moisture conservation, aided sound production, provided a highly sensitive sense of smell, housed a vomeronasal organ, held part of an air-filled pneumatic system… or, getting more speculative, possibly even some sort of inflatable nasal display structure.
Minotaurasaurus ramachandrani skull and head reconstruction
Some ankylosaurids, meanwhile, went with multiple holes instead. Minotaurasaurus here had two additional openings around its nostrils, and Pinacosaurus could have up to five – the purpose of which is unknown. Many ankylosaurs also had forward-facing nostrils (a rare trait in archosaurs) and incredibly complex looping airways through their skulls. These may have allowed for mammal-like "air conditioning", regulating the heat and moisture content of each breath, or perhaps enhanced their sense of smell or served some sort of resonance chamber function. Or, again, maybe even nose balloons.
Also floofy ankylosaur because I can.
Author adminPosted on March 22, 2017 August 9, 2022 Categories paleoart, science illustration, theme months, unsolved paleo mysteriesTags ankylosaur, ankylosauria, ankylosauridae, archosaur, big honking snoots, ceratopsia, ceratopsian, ceratopsidae, chasmosaurinae, dinosaur, excellent snoots, marginocephalia, minotaurasaurus, ornithischia, thyreophora, triceratopsLeave a comment on Unsolved Paleo Mysteries Month #16 – Strange Snoots 2: Oddball Ornithischians