ichnofossil

Grallator

Grallator is probably the most famous genus of dinosaur footprint, and it is the classic theropod footprint model, with the toe pads and the three toed stance. It’s been found in Late Triassic through Early Cretaceous periods and has been made by a wide variety of theropod dinosaur. They’ve been found in the United States, Canada, Europe, Australia, and China, but it’s most common on the North American East Coast, especially the Triassic and Early Jurassic formations of the Newark Supergroup, as shown off in the When Dinosaurs Roamed America special. 

Like so many other theropod footprints (I wonder why), they were thought to be that of birds and were named as such. They were 5 to 15 centimeters long and even though they only show three toes, theropod dinosaurs did have fourth and fifth toes that were too high to leave prints. Sometimes its even possible to estimate what genus of dinosaur left these prints, by comparing proportions in the Grallator prints with dinosaurs in the same formation - Caudipteryx was found to make tracks in the Yixian Formation. 

Grallator tracks in the Newark Supergroup are, of course, the most famous, and were likely to have been made by something similar to Coelophysis. Quite a few ichnogenera have been found to be synonymous with Grallator, given that they were of similar shape and form. 

Sources (Images that are not mine and text): 

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

http://www.baystatereplicas2.com/product/dinosaur-tracks-grallator/

http://projectos.cienciaviva.pt/pw011/jazidas/grallator_anchisauripus_eubrontes_crescimento_alometrico.html

Shout out goes to @magicturtle​!

phenomena.nationalgeographic.com
From Punting to Tromping - Laelaps

External image

A cast of Brachiosaurus stands outside Chicago’s Field Museum.

I grew up with submerged sauropods. In the outdated library books I constantly stuffed my elementary school backpack with, the likes of “Brontosaurus” and other gigantic dinosaurs were almost always lazing about in warm Jurassic swamps. Such bulky animals were too large to have walked on land without crushing their own limbs like jelly, the books said, and sauropods even had their noses on top of their heads to facilitate their subaqueous lifestyle. Zdeněk Burian’s waterlogged Brachiosaurus looked perfectly at home.

And there was more to the argument than incredulity. A curious trackway found the Early Cretaceous rock of Texas recorded the steps of an enormous dinosaur that had apparently dragged its buoyed bulk along an ancient waterway.

A crew working with legendary fossil hunter Roland T. Bird found the traces while scouting sauropod tracks to lay down behind the American Museum of Natural History’s iconic “Brontosaurus” skeleton. Known to the locals long before Bird’s arrival, the numerous sauropod tracks in the vicinity of the Paluxy River were geologically too young to have been made by the New York City museum’s Jurassic sauropod, but prehistoric potholes were nevertheless about the right size and shape for such a sauropod. Among them were a sequence of horseshoe-shaped forefoot prints that surely belonged to a big sauropod, but mysteriously lacked any trace of the hindfeet.

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R.T. Bird’s crew uncovers a different set of sauropod tracks near Glen Rose, Texas

.]

As he and his crew uncovered the tracks during the 1940 field season, Bird wrote in his journal that “I still had hanging over my head a mind-boggling load: forty tons of dinosaur stumping about back at the Mayan Ranch, tromping down the mud on his great feet, and what did he do with the balance of his great body? And how did he balance it? And why?” Sauropods doing handstands required impossible gymnastics.

An isolated impression of the dinosaur’s rear foot seemed to resolve the quandary.  As Bird’s team worked back along the trackway they discovered a partial hindfoot impression just before the impressions of the forefeet changed direction. From the evidence, Bird imagined that:

The big fellow had been peacefully dog-paddling along, with his great body afloat, kicking himself forward by walking on the bottom here in the shallows with his front feet. Deciding to turn back to deep water or onto land, he had kicked his body into an S turn with one push of a hind foot!

Sauropods were often seen more as waders than swimmers, but, at the time, the trackway made sense. The long-necked giants were thought to be far too large to cope with life on land, and the water was the herbivores’ only refuge from the enormous, tearing theropods that had evolved to feed upon them. The trackway evidence was so compelling that even as I gained access to newer books that usually, and rightly, showed Apatosaurus and kin on land rather than in the water, I was still captivated by the image of a bobbing “brontosaur” artist John Sibbick had restored for a 1993 Natural History Museum guide to dinosaurs.

The trouble with trackways is that they’re not always what they seem. Even though tracks are reflections of prehistoric behaviors, the state of the sediment also affects how that behavior becomes preserved. In the case of Bird’s swimming sauropod, an updated understanding of anatomy and sedimentology offer a more prosaic scene of a sauropod tromping about on land.

Bird’s mission was to find tracks for the AMNH’s “Brontosaurus.” This dinosaur, properly known as Apatosaurus, lived roughly 150 million years ago. Whatever sauropod made “swim” tracks, however, lived much later. The Texas site is only about 113 million years old, recording a time after a major changeover in prehistoric North America’s sauropods. Apatosaurus and many of its enormous neighbors were diplodocids, but by the time of the Paluxy tracks this style of sauropod had disappeared and given way to another sort called titanosaurs.

It can be hard to tell just by looking at them, but diplodocids and titanosaurs differed in two ways that helped sink Bird’s swim track story. Whereas Apatosaurus and other diplodocids had a center a mass centered towards their hindlimbs, titanosaurs had a center of mass closer to their middle. Since weight has quite a bit to do with how footprints are preserved, this means that diplodocids were more likely to leave deeper rear footprints and titanosaurs were more likely to leave deeper front footprints.

Then there’s the pattern of the tracks themselves. Tracks and biomechanical studies have shown that diplodocids made “narrow gauge” tracks with their foot impressions arranged relatively close to the midline of the body. Titanosaurs, by contrast, made comparatively “wide gauge” trackways, and the Paluxy traces match the titanosaur pattern.

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Jurassic Park played it safe by showing both standing and wading Brachiosaurus.

]

Anatomy and the dinosaur timeline match a titanosaur – perhaps a dinosaur similar to Sauroposeidon – but there’s one more piece to all this. Even with the front-wheel drive locomotion style of a titanosaur, it’s puzzling why Bird’s trackway only has one edge of a hindfoot impression. The explanation is that the tracks don’t represent the perfectly-preserved impressions the dinosaur left right at the surface, but are undertracks.

When that sauropod walked across the Cretaceous ground, the weight of the animal pushed impressions into the damp layers of sediment beneath the surface. Since the sauropod in question was a titanosaur, this meant that traces of the front feet were better preserved than the rear feet, left only as a partial footprint and an additional disturbance that can just barely be seen. The sauropod wasn’t punting along a lakebottom, but simply walking unhurried.

Other “manus-only” sauropod tracks have been found at various  sites around the world, from Korea to Spain. Similar combinations of anatomy and sediment created these structures. There are swim tracks for other dinosaurs – especially theropods, not so aquaphobic as traditionally thought – but no solid cases for sauropods.

Did dinosaurs such as Diplodocus and Sauroposeidon ever take dips in Mesozoic waterways? Probably. There’s no reason to think that they assiduously avoided water at all costs. But, contrary to what I was taught so long ago, no one has uncovered the fossilized moments of sauropods frolicking in Jurassic swamps or Cretaceous lakes. For a time sauropods were thought to be so dependent on the water that paleontologists asked when, if ever, the giants came onto land. Now we’re left with the contrary question, wondering how such titanic animals could have ever swum.

References:

Bird, R. 1985. Bones for Barnum Brown. Fort Worth: Texas Christian University Press. pp. 160-161

Falkingham, P., Bates, K., Margetts, L., Manning, P. 2011. Simulating sauropod manus-only trackway formation using finite-element analysis. Biology Letters. 7,1: 142-145

Farlow, J. 1992. Sauropod tracks and trackmakers: Integrating the ichnological and skeletal records. Zubia. 10: 89-138

Gardom, T., and Milner, A. 1993. The Book of Dinosaurs: The Natural History Museum Guide. Rocklin: Prima Publishing. pp. 20-21

Henderson, D. 2006. Burly gaits: Centers of mass, stability, and the trackways of sauropod dinosaurs. Journal of Vertebrate Paleontology. 26, 4: 907-921

Lee, Y., Huh, M. 2002. Manus-only sauropod tracks in the Uhangri Formation (Upper Cretaceous), Korea and their paleobiological implications. Journal of Paleontology. 76, 3: 58564

Lockley, M. and Hunt, A. 1995. Dinosaur Tracks. New York: Columbia University Press. pp: 189-191

Vila, B., Oms, O., Galobart, A. 2005. Manus-only titanosaurid trackway from Fumanya (Maastrichtian, Pyrenees): further evidence for an underprint origin. Lethaia. 38: 211-218

Wilson, J., Carrano, M. 1999. Titanosaurs and the origin of “wide-gauge” trackways: A biomechanical and systematic perspective on sauropod locomotion. Paleobiology. 25, 2: 252-267

Breviparopus

Source: http://es.prehistorico.wikia.com/wiki/Archivo:Mano-pie_Breviparopus_IV.JPG

So you know how media coverage of dinosaurs is sadly preoccupied with over the top exceptionalism? Well hold on to your butts, we have an Amphicoelias level situation here. Specifically, Breviparopus is a large sauropod footprint, about 115 cm long COMBINED LENGTH of the front and back feet and 90 cm wide. The tracks are in a 90 meter long series in the Atlas Mountains of Morocco, and the exact time at which they were made is under some debate, dating either to the Oxfordian age of the Late Jurassic about 160 million years ago, or to the Hauterivian age of the Early Cretaceous, about 130 million years ago. Now, we’ve all been doing ichnotaxa together for long enough that we know that there isn’t actually a lot you can extract about the animal making tracks - you can extrapolate some info, but it’s mostly up in the air, and it’s better to try and learn more about how the animal walked and moved, which you can figure out. And yet… 

Source: http://eximinator23.deviantart.com/art/Breviparopus-PrehistoricSize-557168010

Someone decided to make this. Someone thought we could make this. And hence, we’re on the exceptionalism portion of today’s article. Plenty of people have been speculating about these admittedly large tracks, estimating lengths such as 48 meters (based on a misconception that 115 cm was the length of one foot rather than both) and thus the animal was probably about 34 to 37 meters long, making that above image… very very wrong. And yet, still, the fight goes on, and those size estimates are based on the assumption its a Brachiosaurid and not, say a Titanosaur, or a Diplodocid, which depending on what type would change its proportions. It seems likely it was a Brachiosaurid, but what have we learned about ichnofossils? Oh yes, that they can only tell us so much.  

Source: http://es.prehistorico.wikia.com/wiki/Breviparopus

However, it’s also tied to “Brachiosaurus” nougaredi, a problematic taxon that I did not do on ADAD for a very specific reason, thus increasing the amount of confusion and question around this animal. As my friend said on Your Fave is Problematica, “Brachiosaurus” nougaredi

Not Brachiosaurus
Named from fossils that might not be from the same species
Named from fossils that might not be from the same time period
Like Amphicoelias fragilimus, might be one of the biggest animals ever
Like Amphicoelias fragilimus, we lost the fossils that could prove that

So it’s a large trackway that often has its size exaggerated to make the dinosaur that made it bigger so we can talk about the biggest dinosaur ever because for some reason the media - and, thus, the public, and our society - is obsessed with dinosaur size (and violence) rather than actually interesting things about them like how they lived and their behavior and how they evolved and changed over time and yeah. I have a lot of emotions. 

Source: 

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

Shout out goes to @demissiosaurus-ron​!

Scotland’s Sauropods

Over 170 million years ago, on what is now the northern Scottish island of Skye, Sauropods, some of the largest land animals on Earth walked through shallow coastal lagoon as indicated by several overprinting footprints. The new discovery makes the island of Skye the largest dinosaur site in Scotland and fills an important evolutionary gap in the history of these long-necked animals, which were some of the biggest of the dinosaurs.

Keep reading

Eubrontes

Source: http://www.albany.edu/~jdelano/footpr.html

Eubrontes is an ichnogenes of dinosaur trackway form the Late Triassic and Early Jurassic, and have ben found in France, Poland, Slovakia, Italy, Spain, Sweden, Australia, and the USA. Typically lumped in with the genus Grallator, Eubrontes is still an important and common type of theropod footprint. 

Usually they are about 25 to 50 cm long, with three toes and sharp claws. The original describer called the trackmaker a “thick-toed bird” and well, depending on where you stand on the bird political spectrum, he was not wrong. He called them that of a bird and not a dinosaur due to the lack of a dragging tail mark, which, I mean, more testaments to how stubborn people were about dinosaur behavior back in the day. Who knows what we’ll think is ridiculous in a hundred and fifty years?

Source: http://bcornet.tripod.com/MassExt/rockyhil.htm

Dilophosaurus is typically attributed as the trackmaker given its large size; and actually they were the first dinosaur remains found in North America, though they were first called birds. The connection between this footprint and Dilophosaurus was touched upon in the fan favorite documentary When Dinosaurs Roamed America. 

Source: 

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

Shout out goes to @ignicion!

Berninasauropus

Berninasauropus is a theropod track known from the Late Triassic of France. Sadly, I know no more about it. 

Source:

Glut, Donald F. (2003). “Appendix: Dinosaur Tracks and Eggs”.Dinosaurs: The Encyclopedia. 3rd Supplement. Jefferson, North Carolina: McFarland & Company, Inc. pp. 613–652.

Shout out goes to @elinio!

Anomoepus

Anomoepus is a trackway that’s actually fairly well characterized, originally found in the Hettangian age Early Jurassic beds (between 201 and 199 million years ago) of the Connecticut River Valley in Massachusettes, part of the famous Newark Super Group. 

They were made by Ornithischians, though originally they were thought to be evidence of very early birds - this was later disproven through the absence of claws on the rear digits and the number of toes present. It has also had trackways assigned to it from Western Australia. 

It may have been made by an ornithopod, though this is more uncertain, and many consider it to simply be tracks form a basal ornithischian. In fact, various animals that may have made the tracks commonly attributed to Anomoepus include Heterodontosaurus, Lesothosaurus, Scutellosaurus, and Hypsilophodon, the last of which being the only Ornithopod.

It is also unclear if all the trackways assigned to Anomoepus are really from the same ichonogenus, or if it should be split further. The varying species show a wide variation in footprint length, foot width and toe extension, as shown below; however, whether or not this constitutes major enough differences is uncertain. 

Anomoepus trackways have shown varying different types of pace length and style, with one particular trackway showing a slowing of pace legnth and then stopping, with the length decreasing steadily - this could be due to normal behavior or to animal injury. 

(Anomoepus shown in green) 

Anomoepus trackways have often been shown in tandem with the common early theropod trackway Grallator, indicating a possible predator-prey relationship.It is possible that Anomoepus may have been a slower animal, and thus would not have ventured out into open space where it could have been hunted by Grallator; indeed, Anomoepus tracks in open mudflat and lake environments are much rarer compared to theropod trackways. Only one trackway showed evidence of trotting behavior in Anomoepus, indicating that it remained in more crowded environments for safety. 

Anomoepus has also been described in other formations and time periods including the Norian age of the Late Traissic and the Tithonian age of the Early Cretaceous, indicating that the ichonogenus lasted for a long time, further pointing to a basic Ornithischian origin for the animal. At times, imprints have also indicated quadrupedal movement in the animal, as well as various distributions of body weight and stance while walking and standing. A truly fascinating ichonofossil, Anomoepus shows a remarkable amount about how early Ornithischians walked and lived. 

Sources (Images and Text): 

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

Dalman, S. G., and R. E. Weems. 2013. A new look at morphological variation in the ichonogenus Anomoepus, with special reference to material from the lower Jurassic Newark Supergroup: Implications for Ichnotaxonomy and Ichonodiversity. Bulletin of the Peabody Museum of Natural History 54 (1): 67-124. 

Shout out goes to @captainfartarse​!

Buckeburgichnus

Buckeburgichnus is another ichnogenus, specifically one probably from a Megalosaur of some sort. It was found in the Los Cayos Formation in Cornago, La Rioja, Spain, dating to the Aptian age of the Early Cretaceous, sometimes between 125 and 113 million years ago. 

Sources (Text and Images): 

http://en.icnitasdinosaurio.mcu.es/MC/yac_ICNITAS_cayo.html

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

Shout out goes to @fredzillasaurus!

Atreipus

Atreipus is another ichnofossil from the Newark Super Group - clearly a glorious fossil location for dinosaur tracks! Tracks have been found from the Gettysburg Shale in Adams County Pennsylvania, the passaic Formation of Milford, New Jersey, and the Wolfville Formation of Kings County, Nova Scotia. It has three digits with poorly distinguished pads, however they can be found in some specimens. 

The oldest Atreipus fossils ha been found in the Carnian age of the Triassic, and the youngest from the Norian age of the Triassic, straddling a time from of about 9.6 million or 12.4 million years between them. Its footprint features, however, are unknown in any skeletons, and thus trying to assign this footprint to any type of animal has been a struggle - it has been found to be completely incompatible with any known theropods, though it clearly was a very derived archosaur footprint. Hypotheses abound for an early Ornithischian or even a basal dinosaur, or even later Ornithischians like Tenontosaurus (well, something like it, since it came from the Cretaceous). 

It was somewhat similar to Anomoepus though Anomoepus is much more in line with Ornithischians than Atreipus is. What can be concluded is that Atreipus was a dinosaur, or somthing very close to it, but it could either be a more derived ornithischian than Heterodontosaurus or a dinosaur more basal than Saurischians, such as a dinosaur belonging to neither Ornithischia or Saurischia. It had some beginning quadrupedal adaptations and no really close skeletal analogues are known. 

Sources (Images and text): 

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

Olsen, P. ., and Baird, D. 1996. The ichnogenus Atreipus and its significance for Triassic Biostratigraphy: in K. Padian (ed.), The Beginning of the Age of Dinosaurs, Faunal Change Across the Triassic-Jurassic Boundary, Cambridge University Press, New York, p. 61-87. 

Shout out goes to @hipsterdinosauryolo!

Gigandipus

Gigandipus is a theropod trackway type known from St. George, Utah. Originally thought that it would be like a wading bird, or even a huge frog. This was all from before the days of widespread dinosaurs, it seems. 

Gigandipus and Eubrontes are very similar ichnogenera, but Gigandipus has an extra digit in the second phalangeal pad, indicating that it walked differently than Eubrontes, with lower rotation of the toes. However, it is very possible taht the two are simply synonymous. 

Sources (Images and text): 

http://projectos.cienciaviva.pt/pw011/jazidas/icnotaxa_teropodes_triassicofinal_jurassicoinicial.html

http://leefoster.photoshelter.com/image/I0000l0auM0Si.R0

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

Shout out goes to @datgurlkends1!

Anticheiropus

Anticheiropus is a dinosaur footprint gnus from the Connecticut Valley portion of the Newark Supergroup, thus coming from a similar time and place as the ichonogenus from yesterday. It had large digits and was about 20 centimeters long, with no pads from the feet shown on the fossil itself, though the middle digit is clearly the longest in the footprint itself. One of the toes is offset from the rest of the foot, sort of like a thumb, which is where Anticheiropus gets it name. It may have been similar to Anomoepus

Sources: 

http://projectos.cienciaviva.pt/pw011/jazidas/icnotaxa_teropodes_triassicofinal_jurassicoinicial.html

Fossil Footprints of the Jura-Trias of North America by Richard Swann Lull

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

Shout out goes to @justbucketsfull!

Dinehichnus

Dinehichinus is a trackway of an ornithopod, specifically probably a dryosaurid from the Morrison Formation. It was found in Utah and the tracks were typically found in groups traveling together, indicating that it was a social creature. It had three toes greatly split apart as it walked and heel marks, which indicates that as it walked, the animal would have pressed its foot firmly into the ground. 

Sources (images and text): 

http://projectos.cienciaviva.pt/pw011/jazidas/icnotaxa_ornitopodes_cretacicos.html

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

Shout out goes to @unicornsandbutane!

Eutynichnium

Eutynichnium is an ichnogenus of theropod footprint, with three preserved toes and also sometimes the fourth toe that is so often neglected in theropod foot reconstructions. It is probably made by something similar to Megalosauripus, another theropod track genus.

It was made by a medium sized theropod, and were found in Portugal, in the Oxfordian age of the Late Jurassic. 

Sources (Images and Text): 

http://projectos.cienciaviva.pt/pw011/jazidas/megalosauripus_4.html

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

Shout out goes to @jhaycell29!

Deltapodus

Deltapodus was a stegosaurid track type, with actual like, resources about it on the internet. I know, I was as shocked as you were. It was originally reported in Europe, however, tracks have since been found in North America and in China. They’ve even been found in Berriasian-Berremian age rocks, aka the Early Cretaceous, aka when stegosaurs were on their way out. 

The track type has also been found in the Middle Jurassic and the Upper Jurassic, including the Morrison Formation. It’s characterized by three toes on the hindprint and a more oblong shape on the foreprint. It has also been found in Australia, though those foreprints have well defined digits, and were also from the Early Cretaceous. 

It’s very possible that the Asian tracks known come from Wuerhosaurus, bing one of the only stegosaurs known from that time and locality. It is even possible that a nearby skeleton may be the track maker, though that’s under debate. 

Sources (Images and Text): 

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

Xing, L., M. G. Lockley, R. T. McCrea, G. D. Gierliński, L. G. Buckley, J. Zhang, L. Qi, and C. Jia. 2013. First record of Deltapodus tracks from the Early Cretaceous of China. Cretaceous Research 42: 55-65.

Milàn, J., & L. M. Chiappe. 2009. First American Record of the Jurassic Ichnospecies Deltapodus brodricki and a Review of the Fossil Record of Stegosaurian Footprints. The Journal of Geology 117 (3): 343-348. 

Shout out goes to @joedashi!

Carmelopodus

Carmelopodus is a very common ichnofossil found around the world, and is distinctly identified as being a Theropod track, and may even be clearly identified as a Carnosaurian track. 

It has been found in the United States, in England, in Morocco, and plenty of other places, including Dinosaur National Monument, and typically comes from late Jurassic strata, indicating that perhaps even Allosaurus - or something like it - made these prints. 

There are, of course, smaller and larger print types, indicating either ontogenic stages or some smaller related theropods. It distinctly has three toe impressions and usually claw marks. 

Sources (Text and Images): 

http://projectos.cienciaviva.pt/pw011/jazidas/carmelopodus.html

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

Shout out goes to @georgelw!

Banisterobates

Banisterobates is another footprint taxa known both from footprints and handprints, though the latter are small and almost undifferentiated. The describing authors acknowledge that it might be a closely related non-dinosaurian archosaur rather than a dinosaur, which makes its classification rather a mystery. Its possible that it may be Lagerpeton, Marasuchus, Eoraptor or Herrerasaurus - a mixture of almost-dinosaurs and early dinosaurs. 

It’s also possible that the dinosaur was a small ornithischian such as Heterodontosaurus, Hypsilophodon, and Fabrosaurus, or something closely related. It also could have ben Coelophysis or other early theropods. What’s clear is, further analysis of this trackway with the new knowledge we have of Dinosauromorphs is necessary. 

Sources (Images & Text):

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

http://projectos.cienciaviva.pt/pw011/jazidas/banisterobastes.html

Shout out goes to @globesandglitterblog!

Elephantopoides

Elephantopoides was a type of Jurassic sauropod footprint, found in Germany in about 150 million year old rocks. They were probably made along the coast and were also found alongside smaller sauropod tracks and some large theropods. 

Sources (Images and text): 

https://www.flickr.com/photos/danielmennerich/4799340852

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

Shout out goes to @teddyambing!