The Ornithopod Thread- Hadrosaurs, iguanodonts and kin

In Alberta, Canada.

The dino was said to be 30 meters long at first! However, other articles say its 12-15 meters long which is a lot more likely.

http://science.time.com/2013/10/03/pipeline-worker-finds-huge-dinosaur-fossil/

http://www.edmontonjournal.com/technology/Beautiful+dinosaur+fossil+unearthed+near+Spirit+River/8989782/story.html

http://www.ibtimes.com/dinosaur-joe-might-be-most-complete-parasaurolophus-ever-discovered-he-was-found-teenager-1434892#.UmaOBET0n0Q.facebook

http://blog.peerj.com/post/64765520135/dr-farke-and-joe-the-baby-hadrosaur

Dunno about you but I'm happy to hear about this classic dino :B

Apparently there was no such thing as a plain dinosaur.

http://news.nationalgeographic.com/news/2013/12/131212-duckbill-dinosaur-rooster-comb-fossils-paleontology-science/

Yes, in fact you see this with ceratopsians too- the juveniles of different genera/species are almost impossible to tell apart until they grow their characteristic horns and ornated frills, and as you surely know, many small, hornless ceratopsian genera have turned out to be juveniles of better known, larger ones (for example, Brachyceratops is know believed to be a juvenile Rubeosaurus- what was formerly known as Styracosaurus ovatus).

The experiment had already been done with Parasaurolophus in the 90s.

https://asunow.asu.edu/20151021-discoveries-how-speak-dinosaur

Right, higher oxygen levels and all that... good question, I really have no idea

Indeed, if it had been for visual display only they probably would've had soft-tissue crests, akin to those of Edmontosaurus if new discoveries are to be trusted.
Such a complex structure as Parasaurolophus' or Corythosaurus' crest had to serve more than one purpose- kind of like with antelope horns today.

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0145904

https://phys.org/news/2017-04-headless-dinosaur-reunited-skull-century.html

Nice look at a Muttaburrasaurus

http://www.abc.net.au/news/2017-09-04/road-trip-for-a-muttaburrasaurus-from-castlemaine-to-canberra/8852078

https://www.tandfonline.com/doi/abs/10.1080/02724634.2017.1398168?journalCode=ujvp20
(Abstract). 
Suggests Edmontosaurus was capable of quadrupedal gait from the start, rather than starting as obligate bipeds and becoming quadrupeds later on as had been suggested. 
(Below, Maiasaura hatchling, probably similar to the new find)

Weewarrasaurus, a new ornithopod from Australia. Known from a piece of opalised jawbone.

https://www.nationalgeographic.com/science/2018/12/exclusive-sparkly-opal-filled-fossils-reveal-new-dinosaur-species-paleontology/?fbclid=IwAR1RSRXCdzgY-RbT4l85z6OmOans7rYR_Cj-PFf_GZywLQC_wmKKbBILJfk

Not really sure how it difers from other small Australian ornithopods like Laellynasaura and Fulgurotherium, known also from very fragmentary remains...

https://www.eurekalert.org/pub_releases/2019-03/pmon-foo032919.php?fbclid=IwAR3bzkBLWWm4YbJO61m-4PdEzvWA_ABZMY_k5m1DrrHGIbCinRkA_wOuKEg#.XJ44QiNcGz4.facebook

Fostoria, a new iguanodontian described from Australia.

Dinosaur finds consisting of more than one bone are very rare in Australia; in this case, several elements were found, belonging to several individuals.

http://www.sci-news.com/paleontology/fostoria-dhimbangunmal-07265.html

Aquilarhinus, a new hadrosaur

https://www.msn.com/en-us/news/technology/this-shovel-chinned-eagle-nose-dinosaur-lived-in-texas-80-million-years-ago/ar-AAEf8gM?ocid=sf

Fathom wrote: »

Hadrosaurs had great variety. Differential reproduction?

Actually what I find intriguing about them is that postcranially, most of them look VERY much alike, and the head/crest is about the only thing that allows one to tell them apart. Something similar happens with ceratopsians. In both hadrosaurs and ceratopsians it can be extremely difficult even for paleontologists to determine what genus or species they're looking at unless there's a skull, and juveniles (which are yet to develop their distinctive crests) are even more problematic.

Although I suppose the same would be true of say, many antelopes if all we had to go by were the bones...

Fathom wrote: »

Did one species have a snorkel on the top of its head? For breathing at waterline, with rest of animal below surface?

The snorkel idea was once suggested for Parasaurolophus, perhaps the most iconic of the hadrosaurs (although one relatively rare in the fossil record):



The idea has long been discarded due to several reasons:

1. One would expect a snorkel to project more vertically; instead, the crest grows backwards and downwards at the tip.

2. Not all Parasaurolophus specimens have a long crest; in fact, it has been suggested that only adult males did, whereas females and juveniles had much shorter crests. This strongly suggests a role in courtship and social interaction. If the crest was a snorkel we would expect all Parasaurolophus to have the same equipment.

3. Most importantly, there is no opening at the tip of the crest. The animal's nasal passages DO go into the crest but it's just a detour; it is currently believed that the crest functioned not just as a visual display but also as a trombone of sorts, amplifying the dinosaur's calls.

In the 90s, scientists used a computer simulation to calculate how much air a Parasaurolophus would've been able to blow from its lungs, and reconstructed its possible voice. Check it out, it's rather eerie:



Keep in mind that Parasaurolophus is believed to have prefered more forested areas than other hadrosaurs, so it makes sense that sound would've been an important part of its communication.

Also worth mentioning that hadrosaurs as a whole are no longer believed to have been semiaquatic, as was once proposed. The idea was that since they had duck-like beaks, they probably dived to feed on aquatic plants, but this has long been disproven; the beaks were only vaguely reminiscent of those of ducks; in life, they were covered by a rather hooked, sharp keratinous cover to crop vegetation, and they had batteries of thousands of tiny teeth to grind hard food. They weren´t feeding on soft water plants.

Another piece of supposed evidence for their aquatic lifestyle was the fact that a "mummified" hadrosaur was once found which showed what was interpreted to be webbing between its fingers. However, later it was found that this supposed membrane was actually a sort of "mitten" of skin that kept the three central fingers bound tightly together, an adaptation for supporting the animal's weight as it walked on four legs.

Their tail was also not flexible, but rigid and very heavy, and probably one of their main means of defense against predators (they could use it like a sledghammer to strike a predator ). It was not sinuous and crocodile-like as suggested by early paleontologists.

So in short, we have no evidence of aquatic or semiaquatic hadrosaurs as of this moment, and absolutely no evidence of any dinosaurs having snorkel-like crests.

Or hadrosauroid. Skeleton said to be nearly complete and as well preserved as if it had died days ago, thus allowing for great, accurate reconstruction:

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0208480

Big news! Cartilage cells with traces of the original proteins/DNA found in juvenile Hypacrosaurus fossils!



https://newatlas.com/science/dinosaur-dna-proteins-fossils/

These particular specimens were “nestlings”, meaning that at time of death they weren’t yet old enough to leave the nest.

Inside the skull fragments, the team spotted evidence of extremely well-preserved cartilage cells. Two of them were still linked in a way that resembles the final stages of cell division, while another contained structures that look like chromosomes.

The next step was to check whether any original molecules or proteins could still be preserved, and to do so the team conducted two detailed analyses on other skulls from the same nesting ground, and compared the results to samples from young emu skulls that are (obviously) much more recent.

The first was an immunological test, which involves applying a substance that will react if it detects antibodies from a particular cell type. In this case, the test reacted to antibodies of Collagen II, a protein commonly found in the cartilage of animals. This, the team says, suggests that remnants of the original proteins are still present.

Understandably, the reaction was far fainter for the dinosaur samples than the emus. The dinosaurs’ staining was also localized in one spot, where as in the emu it was spread across the whole sample.

In the second test, the team hunted for dinosaur DNA. They isolated individual cartilage cells from the Hypacrosaurus, and applied two different staining substances that bind to DNA fragments. And sure enough, the staining occurred in the same pattern expected for modern cells.

The implications of potentially finding DNA in these samples are huge. Current thinking says that DNA can only persist for about a million years maximum – but these fossils are 75 million years old.

"These new exciting results add to growing evidence that cells and some of their biomolecules can persist in deep-time,” says Alida Bailleul, co-lead author of the study. “They suggest DNA can preserve for tens of millions of years, and we hope that this study will encourage scientists working on ancient DNA to push current limits and to use new methodology in order to reveal all the unknown molecular secrets that ancient tissues have.”

While Jurassic Park remains firmly in the realm of fiction, the possibility that dinosaur DNA and organic molecules could persist for tens of millions of years is still fascinating, and it could teach us far more about these captivating, ancient creatures.

More on the cells and cartilage traces supposedly found in Hypacrosaurus remains (naturally some paleontologists are skeptical, as they were with the T. rex soft tissue a few years ago).

https://gizmodo.com/paleontologists-are-skeptical-about-baby-dinosaur-cells-1842034627