#megapnosaurus

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Dyno Readmore

[Originally posted Mar 17, 2024]

Mohamad Haghani - Carcharodontosaurus feeding on an Ouranosaurus, Spinosaurus fishing out an Onchopristus

Like Asia, Africa was not the first place dinosaurs were found, but after palaeontologists from Britain, America, and Germany started excavation expeditions there, many exciting fossils were found, and continue to be found there today. In particular, a series of German expeditions in the 1910s to Tanzania was the largest fossil excavation in history, and many dinosaurs famous throughout the world have been attributed to this site.

Mesozoic Africa was connected to both South and North America at different stages of time, so dinosaur genera in Africa bear a strong resemblance to many American species that the public are familiar with. Stegosaurs, and Brachiosaurs from North America, Abelisaurs, and Dicraeosaurs from South America, and even a splash of Europe in Spinosaurs. But this melting pot of various dinosaur species have created a unique assemblage of reptiles unique to Africa.

Giraffatitan brancai

Giraffatitan, Phil Wilson

Giraffatitan was an incredibly large sauropod known from Late Jurassic rock in modern Tanzania. Originally, palaeontologists thought that this dinosaur was an African species of the American Brachiosaurus, but it since been given its own genus. Funnily enough if you think to yourself what you think Brachiosaurus looks like, you're probably picturing Giraffatitan, since the fragmentary American specimen has had its head and neck largely based on the much more complete Tanzanian specimen.

Giraffatitan very simply means "titanic giraffe". Macronarian sauropods, which Giraffatitan and Brachiosaurus belong to, have a much more upright, Giraffe-looking neck/shoulder posture compared to the more horizontal neck posture of other sauropods. It was a high browsing animal, eating from treetops, like a... giraffe. It's estimated adult size was about 25m long and 12-15 m tall.

Carcharodontosaurus saharicus

Carcharodontosaurus, Neil Redfield

Carcharodontosaurus was a large therapod described from Late Cretaceous Algeria and Egypt. It's very long genus name actually calls reference to another creatures scientific name the Great White Shark, Carcharadon, which means "Jagged Tooth". So the full name means "Jagged Toothed Reptile from the Sahara".

Originally just described from these shark-like teeth in 1925, Carcharodontosaurus was originally classified as a species of Megalosaurus (the first dinosaur named), but later findings allowed the shark-toothed dino its own genus. It was a large therapod, estimated to be as large or larger than Tyrannosaurus or Giganotosaurus, 12-13 m long and 4-5 m high. It was one of the largest meat eating dinosaurs of all time and probably the apex of ancient North Africa.

Kentrosaurus aethiopicus

Kentrosaurus, Kuzim (deviantart/twitter)

Kentrosaurus was a smaller Stegosaur found from Tanzania. It was a late Jurassic African relative of Stegosaurus, but significantly smaller, and with a different arrangement of ornamentation on its back. Kentrosaurus means "sharp/prickled reptile", and this was due to the range of spines on the dinosaurs back and shoulders. Stegosaurus is well known for its pentagonal plates that continue from its neck all the way to the middle of its tail, but in Kentrosaurus, these plates end just past the shoulders as the rest of the back is lined with large defensive spikes, ending with the infamous thagomizer on the end of its tail. Unique to this genus, it also had large spikes on each of its shoulder blades too. Kentrosaurus was just under a metre tall at the shoulder (not counting spikes), and about 4.5 m long.

Heterodontosaurus tucki

Heterodontosaurus, @viergacht on tumblr

Heterodontosaurus was a very odd basal Ornithischian dinosaur from Early Jurassic South Africa. Ornithichia is the side of the dinosaur family tree opposite to sauropods and therapods. Heterodontosaurus was very unique dinosaur that had a range of traits unique to its specific branch of the dinosaur tree. Heterodontosaurus translates to "different-toothed reptile", and this name reflects the most peculiar aspect of its family.

Heterodontosaurus skull (wikipedia)

Most dinosaur skulls, and indeed, most reptile skulls, have just one type of teeth in their jaws. Meat eaters have the same type of sharp tooth from front of skull to back, plant eater jaws are filled with just plant eating teeth etc. True Heterodonty is a condition mostly associated with mammals, where different parts of the mouth have different shapes, so this dinosaur is truly unique in its clade. It had pointed incisor-like teeth at the front, tusk/canine-like teeth just after that, and blunt, thick molars at the back of the mouth. The arrangement of these teeth are most similar to modern herbivores or opportunist omnivores, so this is the likely diet supposed by scientists.

Coelophysis rhodesiensis/Megapnosaurus r.

Coelophysis, Akeiron (deviantart)

Coelophysis was small, early therapod that lived in the Late Triassic period. This genus has had species described from many places, and in fact, the first species, Coelophysis bauri, was found in North America. Found in South Africa, C. rhodesiensis was originally known as Syntarsus, but this name was already taken a beetle. Then it was long known as Megapnosaurus (meaning "big dead lizard"), but recent studies have found it might be a subspecies of Coelophysis. Coelophysis means "hollow form", referring to the light bone structure of the small bodied dinosaur. This dinosaur is widely known as the poster child of Triassic period dinosaurs, as it is one the most well known early dinosaurs. Unlike many other later therapods its size, paleoartists do not often depict Coelophysis with a thick feather coating, as it was too primitive and early in the tree to have developed much more than a super wispy coating of the most primitive types of feathers.

Rugops primus

Rugops, Raul A Ramos

Rugops was a Late Cretaceous therapod found from Niger. It was part of the Abelisaurid family, a group of dinosaurs with ridiculously functionless arms, long legs, and blunt faces. Rugops was a bit on the smaller side for an Abelisaur compared to South American relatives such as Carnotaurus, at about 1.5 m tall and 5.5 m long. Rugops translates to "wrinkled face", a reference to grooves found along the length of skull, perhaps indicating the presence of a soft tissue crest, but more evidence will be needed to be sure. Given how short Rugops is compare to its active hunting South American relatives, palaeontologists think Rugops would only hunt smaller animals, or possibly scavenged for most of its food.

Dicraeosaurus hansemanni

Dicraeosaurus, Stolpergeist (deviantart)

Dicraeosaurus was a smaller Sauropod from Late Jurassic Tanzania. In stark contrast to Giraffatitan, who had a relatively long neck, Dicraeosaurus had a comically short neck for a sauropod. The Dicraeosaurids, a family of sauropods named after this dinosaur, were evolved for more of a low-browsing lifestyle. Meaning they ate smaller shrubs and ground level plants, leaving the tree-tops for the Brachiosaurs. Its name means "bifurcated head reptile", referring to the large vertebral spines just behind the head, which many paleoartists have reconstructed as a humped neck. These long neck spines are much more exaggerated in its South American cousins Amargasaurus and Bajadasaurus.

Spinosaurus aegyptiacus

Spinosaurus, MALvit (deviantart)

Spinosaurus was a large therapod known from Late Cretaceous Egypt and Morocco . It was part of a group of reptiles called the Spinosaurs (obviously named for Spinosaurus), that had crocodile-like heads, large claws, and lived a generally piscivorous lifestyle. Spinosaurus means "Spined Reptile", referring to its diagnositic tall back spines, which most reconstruct as supporting as membranous sail. The remains of Spinosaurus had been mostly fragmentary for most of the time we'd known the species, so reconstructions were mostly based on related species such as Baryonyx. However, from the late 2000s, more almost complete Spinosaurus specimens have been found, and we now know it was a truly bizarre dinosaur.

Our current understanding of Spinosaurus was that it was a short legged, large armed, paddle-tailed fish eater. Its crocodile-like mouth is only the start of adaptations leaning towards a semi-aquatic lifestyle, and Spinosaurus was probably the best adapted swimmer of any dinosaur we've found. I have written a separate article about the History of our Understanding of Spinosaurus, so if you're intrigued, follow the link there. Spinosaurus was among the largest of all meating eating dinosaurs, at 4-7 m tall, and 14-15 m long. Maybe not as tall as Tyrannosaurus on those little legs, but certainly longer and heavier. Also as an aside, Spino is one of my favourite dinosaurs.

Thanks for Reading

Of course I wasn't able to cover every dinosaur from Africa, so if you wanna know more, I implore you to look more into the topic. What I've shown off here is merely a glimpse into the diversity, and what I personally have thought as more interesting genera.

For next time, I'm thinking of Madagascar and India. Those two regions were originally very separate from Africa and Asia respectively, but they were connected to each other, so have a unique, albeit smaller catalogue of dinosaur species. Links to the previous and next parts of this series will be linked below (when the next one is finished).

About fifteen years ago, a local optometrist named Dr. Sheldon Johnson was doing some construction work on his farm when he uncovered 200 million-year-old dinosaur tracks. I’m not sure what the laws are State to State but, in Utah, should you find fossils on your property you can pretty much do whatever you want with them. Thankfully, instead of continuing on with his excavation plans, Dr. Johnson contacted the right people and opted to preserve the tracks instead. The City of St. George eventually built a museum over that spot and now manage it themselves. And for this, we dinosaur fans owe him a huge debt of gratitude!

The find was so incredible it’s been described by Paleontologist, Dr. Jim Kirkland, as “the most significant dinosaur track site in western North America.” It’s scarce, even by dinosaur track standards, as many animal and plant fossils have been recovered there too. Since the conditions for fossilizing living matter and tracks are very different from each other, scientists are rarely ever given such a complete representation of an extinct ecosystem.

Before guests could view the tracks, however, they must first walk through the museum’s numerous fossil (mostly replica) displays. Many provided plenty of learning opportunities regarding the animals that once roamed (or swam) in Utah. One of the most interesting was a Phytosaur,  semi-aquatic reptile that resembled crocodiles.

I’ve always been a fan of Ceratopsians and Utah boasts many great finds including their own Utahceratops! This was the first time I’d ever seen parts of one on display.

Most of the fossil bones you see at any Natural History museum are replicas since there are few complete skeletons ever discovered and displaying a piece of skull, some chipped vertebrae, and a toe bone ain’t exactly going to “wow” the visitors. To me, as long as the bones are scientifically accurate, it makes little difference.

There was also a room full of faux fossils and interesting facts regarding some of the most fearsome and fascinating animals to have ever existed on the planet in general (and a few that are still here). The museum was both adult and child-friendly and I couldn’t help but wonder how many young minds this location has and will inspire.

Another simple but effective touch was including a plastic model figure next to the bone replicas for added visuals. These past few years have actually been exciting times for prehistoric models (I’m avoiding the word “toy”) thanks to companies such as Papo, Schleich, Safari Ltd, and CollectA (some of which were used by the museum and seen in these photos). While each of these companies has their hits and misses, there’s no denying that their competitiveness has inspired more detailed and scientifically accurate representations as well as depictions of the most recent dinosaur discoveries.

Some tracks discovered at this site didn’t belong to dinosaurs at all. Those included some that were believed to belong to Protosuchus, an ancient reptile and early relative of today’s crocodiles.

Early dinosaurs represented in the tracks were likely Megapnosaurus – pronounced meh-GAP-no-SORE-us. Your probably more familiar with its other name, Coelophysis.

The museum also offered some rare replicas of dinosaurs not related to the tracks at all, such as Scelidosaurus, an early Thyreophoran (armored) dinosaur like the more famous Ankylosaurus among others.

We made it to the tracks and while some were pretty obvious others not so much. Tracks that can’t be directly tied to any specific animal are given the generic name Grallator to indicate tracks made by small, three-toed Therapods (two-legged meat-eaters) such as the Megapnosaurus I mentioned earlier.

Eubrontes is the name given to larger Therapod tracks that were likely made by the twenty foot long Dilophosaurus, a statue of which could be seen in the track area.

Finally, we reached the track site which was surrounded by a walkway so guests could stroll the parameter with signage explaining what they were seeing (and my untrained eye sure needed a LOT of explaining).

Just like today’s healthy lake systems, indicator species such as amphibians existed in Lake Dixie too. This was proven by the discovery of fossilized tadpole nests.

Another amazing find was the presence of dinosaur swim tracks.

After we walked around what had once been the Prehistoric Lake Dixie, we stopped at the Museum’s gift shop. I purchased their book, “Tracks in Deep Time: The St. George Dinosaur Discovery Site at Johnson Farm” which gave an even more in-depth look at this truly amazing place!

Utah is about as close to Dinosaur Heaven we Paleo-fans can get and you’ll definitely want to check out this unique museum!