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My Brachiosaurus reconstructions. The musculature is based heavily off of our extant friend the giraffe. I’ll finish this series off with the skin—I’ll hopefully start and finish it today and have it up here sometime next week. :)
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A reconstruction of a Deinonychus antirrhopus as part of the “Feathered Dinosaurs and the Origin of Flight” traveling exhibit at the Museum of Natural History of Vienna.
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Placodonts:
The placodonts were a strange group of marine reptiles that appeared during the mid-Triassic period but became extinct at the Triassic/Jurassic boundary. They were heavy-bodied swimmers that mostly fed on shellfish; their teeth were specialised for picking shells from rocks and crushing them between their jaws. It is believed that placodonts were not confined to water, and would have been able to travel on land.- Top Picture:
Name: Cyamodus
Pronounced: Sigh-Ah-Mode-Uss
Classification: Placodontia
Sub-family: Cyamodontid
Temporal Range: Middle Triassic (245-228 Mya)
Length: 1.3 metresInformation:
- Discovery:Cyamodus was discovered in Germany, and was officially named in 1863 by palaeontologist Christian Erich Hermann von Meyer. Cyamodus is a member of the placodont family, and more specifically belongs to the placodont sub-family; cyamodontid.
- Description: Cyamodus measured around 1.3 metres in length and its most characteristic feature is the two-part shell or carapace found on the upper surface of the body. The main part of the shell covers the body to the hips and spreads out sideways, almost covering the animals forelimb span. The second part of the shell is smaller in size and covers the animals hips and the base of the tail. Both shell parts are covered in hexagonal and circular plates of armour. The skull is heart-shaped, and is particularly strong at the rear.- Bottom Picture:
Name: Henodus
Pronounced: Hen-Oh-Duss
Classification: Placodontia
Sub-family: Cyamodontid
Temporal Range: Late Triassic (228-220 Mya)
Length: 1 metreInformation:
- Discovery:Henodus was also discovered in Germany, although it was found later than the fossils of Cyamodus, and was officially named in 1936. Like Cyamodus, Henodus is a member cyamodontid family of placodonts.
- Description: Henodus is the placodont which most closely resembles a turtle. There is a carapace covering the whole body which stretches out well beyond the span of the limbs. It is believed Henodus would have acted as some kind of reptilian ray; paddling its broad, flat body along the bed of shallow lagoons, foraging in the sand with its broad mouth. The weak limbs of Henodus suggest that this placodont would not have spent much time on land, and the fact that it is the only placodont not to be found in marine sediment suggests that it lived in brackish or freshwater lagoons.
Picture Source: Kahless28 (deviant art)
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Theropod Of The Day: Tyrannosaurus rex
→ Photo above by subarcticmike on Flickr.
→ T.O.T.D. posts written by crownedrose.Tyrannosaurus rex may as well be the most famous dinosaur to have ever walked the Earth. Its name means “tyrant lizard” in Greek, and rex is “king” in Latin which was pinned by Henry Fairfield Osborn back in 1905, and the massive theropod sure lives up to its name! Below is some interesting information about T. rex for all to enjoy.
⁌ T. rex lived during the Late Cretaceous Period (67-65 Mya) as many know, roaming what is now the western parts of the United States of America and Canada. They measured to be slightly over 40 feet long at maximum, with powerful and elongated hind legs that show an ability to allow a decent speed for such a robust animals. There’s also the thick tail to help with balance, and the iconic (but short) S-shaped neck you see in theropods.
⁌ Contrary to popular belief, T. rex had forelimbs that were not useless. Theories have been brought to the table that they were used during mating rituals, or perhaps to hold down prey (dead or alive). Studying these specimens, T. rex forelimbs show a considerable amount of muscle attachments, making these forelimbs much stronger than previously thought; perhaps being able to curl over 400 pounds with each two digit hand! Not so wimpy anymore, right?
⁌ The tyrannosaur above is nicknamed “Black Beauty” because of the magnesium rich (and well preserved) skeleton, which is on display at the Royal Tyrrell Museum in Alberta, Canada.
⁌ Many know and have heard of Tyrannosaurus “Sue”, which is my favourite dinosaur skeleton in the world! She is the largest, most complete, and best preserved Tyrannosaurus rex ever discovered. Her skeleton has given us an endless amount of information towards the life and biomechanics of tyrannosaurids, and dinosaurs in general of the Mesozoic. You can read extra information I’ve written up about Sue here.
⁌ Unlike their depiction in Jurassic Park, Tyrannosaurus rex had binocular vision, which gave them great eyesight to hunt and scavenge for their prey. If you look at their skull, it is shaped like a triangle; the front of the skull is slender which then widens out to the back of the skull. This structure helped T. rex to have this vision, which suggests that it was a hunter. Many years ago it was thought T. rex only scavenged for food, but the hunter/scavenger debate is one that still goes on to this day in palaeontology, plus the theories of Tyrannosaurus engaging in cannibalism is on the table!
⁌ Ever heard of their teeth being called ‘bananas’? Tyrannosaurus had teeth with heterodonty, which means that their teeth changed shape depending on their position in the jaws (just like us)! Everyone knows the teeth T. rex had, which are massive, thick with reinforced ridges, and shaped like bananas which in tandem with the jaw power of T. rex, made for a deadly crushing bite. The premaxillary teeth at the front of the jaws helped as well for them to not break off during feeding due to their shape (and those ridges!). T. rex as well also replaced teeth, just like sharks do. We’ve found this out because of well preserved fossils that show new teeth coming in around full grown ones.
⁌ Their skull is one to be reckoned with, evolution having a field day to make for a powerful killer. Unlike other theropods, T. rex had a U-shaped upper jaw at the tip, strengthening its power to create bone crushing jaws which could deal with much stress in tearing off meat. Having such a massive skull would be heavy, but luckily (like other theropods), T. rex had many ways to lighten the weight by having large openings in the skull, along with certain bones showing to be fused and have skeletal pneumaticity. Read more about theropod skull comparison here.
⁌ The growth rate of T. rex was very fast, and one of the most changing during their lifetime. If you compare a youngster and adult tyrannosaur, you will see how much they morph. From having knife-like teeth and elongated heads when young, they grow up to have a much wider and robust head with those banana teeth like I stated above. Because of this dramatic change, some discoveries of young tyrannosaurs are thought to be a new genus of tyrannosauridae (ever hear of Nanotyrannus?). Many still debate whether or not Nanotyrannus (and even other tyrannosaurs) is a new genus, and more research is still being done to weave out these questions.
Also, I just want to end this post with a big thank you to everyone who has encouraged me to write this series, and for reading my ridiculously long posts! I tend to get very excited when I write these up, and I tried my best not to go too in depth on every aspect of Tyrannosaurus rex, though it all is extremely interesting. If anyone would like more information on T. rex - like locomotion, anatomy, feeding habits, fossil history, etc - just send me a message! I’m always willing to answer questions on theropods for the curious minds out there. I hope you all have enjoyed reading this, and be sure to keep a look out for future T.O.T.D. posts!
Theropod Of The Day Links:
I’m obsessed with dinosaurs and I’m a walking cliche with this magnificent beast being my favourite :) You should all follow this blog.
(via khubsoorat-deactivated20130218)
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The Triassic is a period of time which extends from 251 to 199.6 Mya (million years ago). The name Triassic was coined by German geologist Friedrich Von Alberti in 1834, and relates to the three distinct rock layers that formed during the era. These rock layers can be seen throughout Germany and northwestern Europe and are formed of a layer of red beds, capped by a layer of chalk, followed by black shales.
Fauna:
The Triassic follows a period of time known as the Permian, and began in the wake of the Permian-Triassic extinction event; an event which left the Earth’s biosphere impoverished. Terrestrial life did not fully recover and diversify until midway through the Triassic era. The shelled, marine-dwelling, ammonites recovered, expanding from a single line which survived the Permian extinction. The fish fauna for the period remained very uniform, highlighting the fact that very few fish families survived through to the Triassic. Despite this, there were a large number of marine reptiles present throughout the Triassic. These included pachypleurosaurs, nothosaurus, placodonts, the first plesiosaurs and the highly successful ichthyosaurs.
On land, the early Triassic period was dominated by basal amphibians and a handful of therapsids (the ancestors of mammals), which had managed to survive the extinction event. However as the Triassic period progressed the therapsids were slowly displaced by archosaur reptiles (the ancestors of dinosaurs). The increase in archosaur numbers likely forced the surviving therapsids and their mammalian succesors to live as small, mainly nocturnal insectivores. The archosaurs on the other hand, evolved at a rapid pace, with different clades of archosaur evolving into different things. By the mid-Triassic the first pterosaurs and dinosaurs were present; but shared land space with a number of other reptile groups, including the aetosaurs, the rhynchosaurs, the first turtles, and the first crocodilians (the sphenosuchians).Geography & Climate:
During the Triassic, almost all the Earth’s land mass was concentrated into a single supercontinent, known as Pangea. The mid-Traissic saw Pangea begin to gradually rift into two separate landmassed, Laurasia to the north and Gondwana to the south. The global climate during the Triassic was mostly hot and dry, with deserts spanning much of Pangaea’s interior. However, the climate shifted and became more humid as Pangaea began to drift apart. There is no evidence of glaciation at or near either pole; in fact, the polar regions were apparently moist and temperate, a climate suitable for reptile-like creatures.This following few weeks will be dedicated to all things Triassic! To begin with we will look at all the non-dinosaur animals which lived during the Triassic period, and eventually build this up into some detailed Triassic dinosaur fact-files. So if there is a Triassic dinosaur you want a fact-file about, please, please, please let me know!
Dinosaurs are a diverse group of animals that were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous. Also; you will find a lot of random extinct reptiles being posted here that aren't technically "dinosaurs" (not included in the superorder), but are from the Mesozoic era.
Triassic Period
Jurassic Period
Cretaceous Period
