#iguanacolossus

[makairodonx]

Utahraptors drinking by the steam, 136 million years ago - a scene from the Cedar Mountain Formation featuring many of the creatures form that formation

[randomanimaloftheday]

Day 197#: Iguanacolossus fortis

Merry day twenty-six of Dino-December! Today's animal of the day is Iguanacolossus fortis!

Image credit: cisiopurple on DeviantArt

As its name suggests, this species of Early Cretaceous ornithopod dinosaur is a North American relative of the iconic Iguanodon. It was similar in size to its European cousin, around 30 ft long, and probably looked similar too, or at least we think it did since there's not a ton of fossil material for this dinosaur. Despite this, Iguanacolossus is considered to be one of the largest ornithopod dinosaurs to live in North America during the Early Cretaceous. Even though there isn't any direct fossil evidence for it, Iguanacolossus likely possessed the iconic iguanodontid thumb spike, which it would have used to defend itself against predators by stabbing its would-be attackers, such as the fearsome Utahraptor! In addition to this large dromaeosaur, Iguanacolossus would have lived alongside the primitive therizinosaur Falcarius, an armored nodosaurid called Gastonia, and a pterosaur known as Hippodraco. EDIT: Hippodraco is actually another type of iguanodontid. I have no idea why I thought it was a pterosaur. I tried looking up if there was a pterosaur with a similar name like "Hippodrakon" or something but there isn't. Sorry to anyone to read this before I realized my mistake. Whoops!

[extinctworld-ua]

Iguanacolossus

Iguanacolossus — рід ігуанодонтових орнітоподових динозаврів, що мешкали в Північній Америці в ранньому крейдяному періоді.

Повний текст на сайті "Вимерлий світ":

https://extinctworld.in.ua/iguanacolossus/

[actual-haise]

A solitary Iguanacolossus observes an approaching storm in prehistoric Utah, 130 million years before today.

[a-dinosaur-a-day]

Iguanacolossus fortis

By José Carlos Cortés

Etymology: Colossal Iguana

First Described By: McDonald et al., 2010

Classification: Dinosauromorpha, Dinosauriformes, Dracohors, Dinosauria, Ornithischia, Genasauria, Neornithischia, Cerapoda, Ornithopoda, Iguanodontia, Dryomorpha, Ankylopollexia, Styracosterna

Status: Extinct

Time and Place: Between 129 and 123 million years ago, sometime between the Barremian and Aptian ages of the Early Cretaceous 

Iguanacolossus is known from the Yellow Cat Member of the Cedar Mountain Formation in Utah 

Physical Description: Iguanacolossus was a large, bipedal herbivore, similar in general shape to the earlier Camptosaurus from the same region of North America. As its name would suggest, it was fairly large and robust, reaching 9 meters long and 3 meters in height at the hip - making it longer than the width of a truck and much taller than a person. Known from decent, if scattered, remains, we have parts of the legs, tail, hips, back, and skull. However, we do not have the hands of this dinosaur; though it was touted as being a thumb-spiked dinosaur, we can’t actually be certain it had a large one; most members of the group have reduced thumbs spikes, rather than the large and distinctive structure of Iguanodon itself.

Iguanacolossus had a long, narrow skull, filled with teeth for chewing up plant material, and a beak to aid in snipping off leaves prior to chewing. Its teeth had thickened enamel, to aid in chewing. Iguanacolossus would have slid its lower jaw into its upper jaw to chew, using the serrations created by the closely packed teeth to slice up the plant material. Iguanacolossus would have had a thickened tail to aid in walking, and a thick, muscular neck.

Though only one specimen of Iguanacolossus is officially described, more specimens from juveniles and subadults are known and assigned to the genus in a thesis publication; an official peer-reviewed article is necessary to definitively assign these bones to Iguanacolossus, but for now the association seems likely given they come from the same time and place, and they have similar morphologies. These skeletons indicate that Iguanacolossus went through very rapid growth during development, aiding in reaching such a large size. This also helps to point to Iguanacolossus being warm-blooded and active (as is probably the case for all dinosaurs). In fact, Iguanacolossus shows growth patterns similar to the later Maiasaura, indicating that hadrosaur-like growth and development evolved quickly in their family tree.

Given its large size and relatives with scales, Iguanacolossus would have been mostly, if not entirely, scaly. Any feathers left on its body would have been ornamental - for display only.

Diet: Medium-level browser of plant material; Iguanacolossus would have been able to eat tough vegetation given its increased chewing abilities and strong enamel. 

By Lukas Panzarin, CC BY 2.5

Behavior: Given that Iguanacolossus was found with one single specimen, and its relative Iguanodon was actually a fairly solitary animal, it’s likely that Iguanacolossus would have traveled and fed alone in its environment, only congregating into groups to take care of its young. It’s possible, however, given the probable group of juveniles collected elsewhere, that the young did congregate together until reaching maturity. Their large size at this point would have allowed Iguanacolossus to take care of itself just fine without help from other members of the herd. This would have allowed individual Iguanacolossus to find more food on its own, which, combined with its ability to chew tough plant material, indicates at least some seasonal changes in vegetation that reduced the amount of soft plants to eat.

Ecosystem: Given the presence of extensive mudstone and other evidence of water in the Yellow Cat Member, this represented a fairly wet time in the history of the region, as opposed to other times in the Cedar Mountain Formation or the early Morrison Formation that were marked with extensive arid climates. Lakes and rivers filled the floodplain region and provided a variety of habitats for Iguanacolossus to move around in. Still, it would have been semi-arid, and its possible that the mudstones were the result of seasonal changes in water level.

Iguanacolossus shared its environment with a variety other dinosaurs, including the other Ornithopods Hippodraco and Cedrorestes; the ankylosaur Gastonia; the sauropods Mierasaurus and Cedarosaurus; the early Therizinosaurs Martharaptor and Falcarius; the large (and weird) Dromaeosaur Utahraptor and the somewhat more normal Dromaeosaur Yurgovuchia; the Troodontid Geminiraptor; and the early Ornithomimosaur Nedcolbertia.

Non-dinosaurs were present as well, of course - notably the tuatara relative Toxolophosaurus, turtles such as Glyptops; multiple types of fish; and the mammal Cifelliodon.

Other: Iguanacolossus may have been able to walk quadrupedally, but that’s difficult to determine without forelimb fossils.

~ By Meig Dickson

Sources under the cut 

Burton, D., B. W. Greenhalgh, B. B. Britt, B. J. Kowallis, W. S. Elliot, R. Barrick. 2006. New radiometric ages from the Cedar Mountain Formation, Utah and the Cloverly Formation, Wyoming: implications for contained dinosaur faunas. Geological SOciety of America Abstracts with Programs 38 (7): 52.

Carpenter, K. 2006. Assessing Dinosaur Faunal Turnover in the Cedar Mountain Formation (Lower Cretaceous) of Eastern Utah, USA. Mesozoic Terrestrial Ecosystems 21 - 25.

Garrison, J. R., D. B. Brinkman, D. J. Nichols, P. Layer, D. L. Burge and D. Thayn. 2007. A multidisciplinary study of the Lower Cretaceous Cedar Mountain Formation, Mussentuchit Wash, Utah: a determination of the paleoenvironment and paleoecology of the Eolambia caroljonesa dinosaur quarry. Cretaceous Research 28:461-494

Kirkland, J.I., S. K.Madsen. 2007. The Lower Cretaceous Cedar Mountain Formation, eastern Utah: the view up an always interesting learning curve. Fieldtrip Guidebook, Geological Society of America, Rocky Mountain Section. 1-108 p.

McDonald, A. T., J. I. Kirkland, D. D. DeBlieux, S. K. Madsen, J. Cavin, A. R. C. Milner, L. Panzarin. 2010. New basal iguanodonts from the Cedar Mountain Formation of Utah and the evolution of thumb-spiked dinosaurs. PLoS One 5 (11): e14075: 1 - 35.

Miller, R. D. 2016. The Lower Cretaceous Cedar Mountain Formation of eastern Utah: A Comparison with the Coeval Burro Canyon Formation, Including New Measured Sections on the Upcompahgre Uplift. UtahState University All Graduate Plan B and other Reports: 829.

Sartin, C. E. 2017. An Osteohistologic Analysis of Growth in Ornithopoda. Johns Hopkins University Graduate Thesis.

[makairodonx]

An illustrated assortment of some of the various dinosaurs (all of them shown not to scale for convenience) that inhabit the semiarid Early Cretaceous neighborhood of Utahraptor ostrommaysorum. Among the most unusual of these neighbors are the indeterminate sail-backed Iguanodontian that has still not been formally described, the small but highly-enigmatic Therizinosaur Martharaptor, and the Turiasaurid Mierasaurus, which is a rare Cretaceous and North American representative of an otherwise mainly Jurassic and European family of sauropods.

[tales-of-kaimere]

"A female Utahraptor ostrommaysorum grapples with a large adult Hippodraco, enduring a bite to her hand as she dispatches her prey with several stabs to his throat with her enormous killing claw..." Utahraptor was an extremely unusual member of the dromaeosaur, or 'raptor', family. The anatomical features of this genus are so deviant from the norm that I believe we can expect them to hunt quite differently from their kin. I discuss these ideas more thoroughly in my Utahraptor lateral study here: Utahraptor. As I suggest there, I think Utahraptor would not employ the tactic preferred by others of its kind. Many paleontologists believe other dromies leaped atop their prey, used their wings and rigid tails to remain balanced as they dig at prey with their talons and wounded them with bites. The wings could have been beaten down to further disoriented prey. This strategy suits their anatomy well, but as evidenced by the famous 'Fighting Dinosaurs' fossil, this was not the only card in their hand. Sometimes, perhaps most often against larger prey or when desperate, dromaeosaurs would grapple their prey, striking with their wings and stabbing the notorious 'killing claw'. With a flexible tail, straighter claw better suited for stabbing than hooking, and short yet strong arms, I think this would be a method that Utahraptor might employ more often than its relatives. Maybe they used their strong arms to grab prey's heads to keep them from biting the predator, but as shown by the 'Fighting Dinosaurs' fossil, this left their hands vulnerable to bites. There must surely be a place for the gigantic head of Utahraptor. I've hinted at it here: a bite to the flank of her prey. As prey ran, the Utahraptor might open with a few bites to weaken their targets with shock and blood loss. After a few bites, Utahraptor would then tackle their prey to the ground, slap them with their arms to keep them disoriented, then dispatch them with the massive killing claws on their feet to the throat. As a counter to this, I bulked up the neck of my Hippodraco with speculative thick skin that I talk about in more detail on my Iguanodon lateral. This could have offered some protection against the killing claw strikes, but after several stabs, chances are good that one would hit a major artery or the windpipe. This is riddled with speculation, so take that all in its stride. I'm just trying to make sense of how strange Utahraptor is. Such an amazing animal! I look forward to learning what more secrets have yet to be revealed by the many Utahraptors fossils awaiting preparation. Check out the Utahraptor Project and if you can, donate to help the project along! Cheers! -Keenan Fighting Dinosaurs:  www.amnh.org/exhibitions/fight… Utahraptor Project: www.gofundme.com/utahraptor More of my illustrations, along with cards, prints, mugs, and more! www.illustratedmenagerie.com/p…

[a-dinosaur-a-day]

Iguanacolossus fortis

By José Carlos Cortés on @ryuukibart​

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Name: Iguanacolossus fortis

Name Meaning: Colossal Iguana

First Described: 2010

Described By: McDonald et al. 

Classification: Dinosauria, Ornithischia, Genasauria, Neornithischia, Cerapoda, Ornithopoda, Iguanodontia, Dryomorpha, Ankylopollexia, Styracosterna

Iguanacolossus is a large Styracosternan known from the Cedar Mountain Formation in Utah. It lived about 130 million years ago in the Barremian age of the Early Cretaceous, alongside a wide variety of dinosaurs from that formation. It was roughly 10 meters long and 3 meters tall, and is known from scattered, but decent remains, including part of the skull. Being from the Yellow Cat Member, it lived alongside such dinosaurs as Gastonia, Cedrorestes, Hippodraco, Cedarosaurus, Falcarius, Geminiraptor, Martharaptor, Nedcolbertia, Utahraptor, and Yurgovuchia. 

Source:

https://en.wikipedia.org/wiki/Iguanacolossus

Shout out goes to @giant-hobbit!