The Spinosauridae Thread

Adam Khor

Ichthyovenator, an Asian spinosaur

With two sails!

It was a baryonychine, 7 to 9 meters long, found in Laos. Paper is restricted, unfortunately.

http://www.springerlink.com/content/r5x213648388tt23/

Ichthyovenator thus becomes the first confirmed spinosaur from Asia.

Galvasean

"Fish hunter" - love it.
Looks like something took a bite out of its sail.

Rubecula

Galvasean wrote: »

"Fish hunter" - love it.
Looks like something took a bite out of its sail.

If there was something around taking a bite out of a spinosaur, I for certain wouldn't fancy meeting one in a dark alley, whatever it was.

Nice find Adam.

Galvasean

Interestingly, Dinosaur Tracking commented that the paper also mentioned a finger bone from late Jurassic North America previously attributed to Torvosaurus may have actually belonged to a spinosaur, which would make it not only the first spinosaur known on that continent, but the oldest of its kind yet!

Adam Khor

Galvasean wrote: »

Interestingly, Dinosaur Tracking commented that the paper also mentioned a finger bone from late Jurassic North America previously attributed to Torvosaurus may have actually belonged to a spinosaur, which would make it not only the first spinosaur known on that continent, but the oldest of its kind yet!

But c´mon, a vile finger bone? :S

Adam Khor

Spinosaurs ate like giant pelicans

http://blogs.discovermagazine.com/d-brief/2016/01/11/spinosaurus-devoured-meals-like-a-giant-pelican/#.VpgqRLbhAsY

The dinosaur in the picture is Sigilmassasaurus, which has recently been proposed as a valid genus again, but is still just a bunch of measly bones so don´t give much credit to the reconstruction.

Rubecula

nice pic though

Adam Khor

On Brazilian spinosaurids

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0187070

Adam Khor

How spinosaurs, carcharodontosaurs and crocodiles managed to coexist

http://blogs.discovermagazine.com/deadthings/2018/04/10/dinosaur-diet-tips-apex-predator/#disqus_thread

Adam Khor

Juvenile Spinosaurus claw found in Morocco

The pedal claw shows the same flattened shape as the ones associated with adult Spinosaurus (suggesting the young too were aquatic) and came from a specimen maybe 1.78 meters long, the smallest Spinosaurus of which evidence has been found. Sadly no full or even partial skeleton of a baby Spinosaurus is known, so we don´t know if they were born with the sail or if it was developed later as the animal reached maturity.
https://peerj.com/articles/4785/

Adam Khor

Study challenges aquatic Spinosaurus hypothesis

Using computer models this study suggests Spinosaurus may not have been as well adapted to an aquatic lifestyle as was previously suggested.

https://peerj.com/articles/5409/

I'm never quite convinced by computer models, though. There's just too much we don´t know about the animal's inner workings, and no complete skeleton has been found thus far, so...

Adam Khor

Spinosaurus was a widespread, long lived genus

This review of Spinosaurus finds across Africa suggests Spinosaurus to have been a widespread genus that lasted for a very long time, and that remains are likely to be found in Europe and South America as well.



https://pubs.geoscienceworld.org/sgf/bsgf/article/565723/large-sized-theropod-spinosaurus-an-important

In fact, remains may have been found in South America already. The so called "Oxalaia" is a fragmentary snout from a large (14 m) spinosaurine, which may very well be Spinosaurus itself:

Adam Khor

Juvenile Spinosaurus coexisted with adults, probably associated with them

Study shows juvenile Spinosaurus were occupying the same habitat as the adults, and may have kept close to them for protection as happens with some crocodilians nowadays.

https://www.sciencedirect.com/science/article/pii/S0195667118302052

Adam Khor

Yet another study supports the idea of Spinosaurus as an aquatic predator. Furthermore, it suggests spinosaurs took over the niche of apex predator in the river systems of Cretaceous Africa (and South America?) after the extinction of giant pholidosaurs (crocodile-like creatures such as the famous Sarcosuchus imperator).

https://www.sciencedirect.com/science/article/pii/S0195667117303427

Adam Khor

Although rather fragmentary, Vallibonavenatrix is the first spinosaur from Spain that can confidently be classified as a distinct form (most spinosaur remains from Spain have been tentatively associated with Baryonyx, which lived at the same time).

https://www.sciencedirect.com/science/article/pii/S0195667119301302?fbclid=IwAR3kyV4CTLZgeEZQMJMb-yLxOYnr4aUoPSxkNKbHQlMHQi_RNB3MvFFBNFA

Vallibonavenatrix seems to be a spinosaurine, more closely related to Spinosaurus itself and the Brazilian Irritator/Angaturama than to Baryonyx.

Adam Khor

Spinosaurus (and Carcharodontosaurus) lived in a world of frequent wildfires

Or at least those from the famous Bahariya Formation of Egypt did.

https://journalofpalaeogeography.springeropen.com/articles/10.1186/s42501-019-0042-6

The occurrence of charcoal as evidence of repeated wildfires is in good agreement with palaeoclimatic interpretations for the Bahariya Formation. Based on palynological studies, a number of authors reconstructed a tropical warm and semi-arid climate during deposition of this formation (e.g. Abdel-Kireem et al. 1996; Ibrahim 2002). Such climatic conditions, with a marked and prolonged dry season, can promote the ignition and spread of wildfires (e.g. Scott et al. 2014), especially when the atmospheric oxygen concentration is assumed higher than today

Adam Khor

Big news regarding Spinosaurus! An almost complete and partially articulated tail from a subadult individual has been excavated and reconstructed, and turns out to have tall neural spines giving it a flattened, fin-like shape not unlike the tail of a newt.

The tail appears to have been quite flexible (something that had been hinted before but not yet confirmed by more extensive fossils), proving that Spinosaurus swam not by paddling on the surface like a giant duck (as suggested not so long ago), but by propelling itself with the tail. It was a truly aquatic predator, chasing after prey in and underwater.

The discovery also makes the Spinosaurus neotype (to which the tail belongs) the most complete ever found, AND the most complete dinosaur known from continental Africa, quite the development considering it was, for the longest time, known only from fragmentary remains that were destroyed during a WWII bombing.

https://www.nationalgeographic.com/science/2020/04/first-spinosaurus-tail-found-confirms-dinosaur-was-swimming/






Spinosaurus has gone through quite the evolution even after its extinction. Originally envisioned as a standard theropod with an inexplicable sail on its back:




To a more slender-jawed version that would eventually inspire the Jurassic Park III portrayal that made the animal famous to mainstream audiences:




To the controversial 2014 reconstruction many refused to believe due to the extreme divergence from the typical theropod body plan:




To this, even more extreme version.



Proof that dinosaurs were stranger and more diverse than usually given credit for. :cool:

Adam Khor

New paper on spinosaurids suggests the Brazilian "Oxalaia" and the North African "Spinosaurus marocannus" and "Sigilmassasaurus" are in reality synonyms of Spinosaurus aegyptiacus. This confirms Spinosaurus was quite widespread, which is to be expected from such a large, apparently largely aquatic animal.

This has been a great year for Spinosaurus- three papers have been released on it in one month!

https://www.sciencedirect.com/science/article/pii/S0195667120302068

Adam Khor

Brazilian spinosaurid Irritator's skull analysis confirms adaptations for piscivory:

https://www.nature.com/articles/s41598-020-66261-w#disqus_thread

Most interestingly, the snout was held downwards and angled in such a way that it could be submerged while keeping the eyes and nostrils above the water surface.

Adam Khor

Study finds evidence of three possible spinosaurids in the early Cretaceous of Spain (Baryonyx, Vallibovenatrix, and possibly Caramillasaurus, formerly thought to be a ceratosaur).

https://link.springer.com/article/10.1007/s41513-020-00138-9

Adam Khor

Spinosaurus probably not a fast aquatic predator, more of a wader, study suggests:

https://phys.org/news/2021-01-behaviour-giant-carnivorous-dinosaur-spinosaurus.html