palaeopathology

[theropod]

STEGOSAURIAN MARTIAL ARTS: A JURASSIC CARNIVORE STABBED BY A TAIL SPIKE, EVIDENCE FOR DYNAMIC INTERACTIONS BETWEEN A LIVE HERBIVORE AND A LIVE PREDATOR

BAKKER, Robert T.1, ZOEHFELD, K. Weidner1, and MOSSBRUCKER, Matthew T.2, (1) Department of Paleontology, Houston Museum of Natural Science, 5555 Hermann Park Drive, Houston, TX 77030-1799, [e-mail], (2) Morrison Natural History Museum, 501 Colorado Highway 8, Post Office Box 564, Morrison, CO 80465

Were carnivorous dinosaurs active predators, killing their own prey, or scavengers depending upon carcasses found dead, or a mixture of both? Today, large herbivores -- buffalo, rhinos, hippos -- often fight back, damaging the attackers. Many dinosaurian herbivores carried horns or spikes or other potentially dangerous weapons. Such armament may have functioned in defense, courtship displays and intraspecific combat. If dinosaurian predators regularly attacked well-armed herbivores, we would expect to find predator skeletons with wounds that can be attributed to particular herbivores.

We have analyzed an adult allosaur skeleton from the Brushy Basin Member of the Morrison Formation, Late Jurassic, Albany County, Wyoming. A stab wound penetrated through the lower pubis, piercing the entire pubic “boot”. A massive infection ate away a baseball-sized sector of the bone; probably this infection spread upwards into the soft tissue attached here, the thigh muscles and adjacent intestines and reproductive organs. Lack of healing in the wound indicates that the allosaur died from the consequences of the strike.

The wound has the shape of a cone. The size and shape match that of stegosaur tail spikes from specimens dug in the same strata. The strike appears to have come from directly below the allosaur. To deliver a vertical blow, a stegosaur would have to twist the tail tip because in normal posture the spikes point outward and backward. Stegosaur tails are unusual: near the hips the tail muscles were massive; functional accessory joints (zygapophyses) and muscle attachments continue far distally to the tail tip. We interpret such tail specializations as providing both power and precision in the direction of the spike trajectory. Therefore we interpret the allosaur as a victim of herbivore defense.

from here: gsa.confex.com/gsa/2014AM/webprogram/Paper247355.html

That sounds pretty spectacular. the stegosaur must have moved its tail end in laterodorsal or posterodorsal direction at a rather odd aangle to hit the pubic boot from below, and yet it managed to puncture right through one of the most massive bones in the theropod skeleton. And that infection sounds pretty damn bad!

Here’s an image:

© phys.org/news/2014-10-kung-fu-stegosaur.html

[creature386]

A sub-adult Allosaurus fragilis (MOR 693) was discovered in 1991 in the Upper Jurassic Morrison Formation of Big Horn County, Wyoming. Examination of the specimen reveals pathological conditions on five dorsal ribs, gastralia, cervical vertebra, three dorsal vertebrae, caudal vertebra, chevron, scapula, manus phalanx, ilium, two metatarsals, and two pes phalanges. Detailed description of these bones includes classification according to probable cause (i.e., traumatic; infectious; traumatic-infectious; developmental; idiopathic). In addition to the paleopathological analysis of MOR 693, descriptions and interpretations are given from a study in progress of pathological abnormalities in the Cleveland-Lloyd Dinosaur Quarry collection. This study provides a model for future paleopathological analyses, emphasizing that description of the location, extent, and texture of an abnormality is crucial, since interpretations are subject to change.

This analysis discusses physiological implications of the abnormalities in MOR 693 and suggests probable behaviors and environmental influences resulting in injury and infection. Lifestyle and behaviors that likely predisposed allosaurs to injury and infection include pursuit of prey, intra-specific competition for mates, and intra- and inter-specific rivalry for carcasses and territory. Ultimately, paleopathological analysis of a large sample of dinosaur bones may reveal that certain abnormalities characterize taxa, and are diagnostic of specific behaviors, environmental influences, and physiology

www.tandfonline.com/doi/abs/10.1671/0272-4634(2002)022[0076:MIAIIA]2.0.CO;2#.VEamwiig3Cc

[theropod]

Infinity Blade

Jun 10, 2014 16:44:00 GMT 5 theropod said:

Jun 10, 2014 3:33:38 GMT 5 Infinity Blade said:

I believe thesporerex posted the above image elsewhere; apparently it's the Allosaurus specimen with a broken lower jaw that of course healed (supposedly the inspiration for the Allosaurus in Dinosaur Revolution nicknamed 'Broken Jaw'). Though, these are only two instances of what theropods endured.

I don't think that's the fossil that served as an inspiration for DR. If I recall correctly they actually showed it was "Labrosaurus":
This specimen:
en.wikipedia.org/wiki/Allosaurus_fragilis#mediaviewer/File:Labrosaurus.jpg

The skull above looks remarkably similar to big al two (SMA 0005) if you ask me, to the point where I'd say it is probably a cast of that specimen.
www.bhigr.com/store/product.php?productid=306

This was published today:
peerj.com/articles/940/
The first scientific paper giving some details about Big Al 2, which apparently is also similar to Big Al in terms of its pathological record.

It appears you were right about the dentary being pathological, since SMA 0005’s dentary is, the distinctive shape makes it quite clear that that’s the same specimen:
The inspiration for Dinosaur Revolution was definitely USNM 2315 though: www.youtube.com/watch?feature=player_detailpage&v=6TosGbfN3JA#t=558

[Infinity Blade]

theropod

I recently found this publication, which may or may not be of interest to you in consideration of our earlier talk of a tyrannosaurid's chances of subduing its similarly gigantic prey.

There were more muscles present elsewhere on the ceratopsian body than on the skull, thus implying that the skull/ face was likely attacked by the tyrannosaurid for one purpose to bring the ceratopsian down in order to feed upon it.

The pattern and distribution of the tooth traces on the ceratopsian skull extend our knowledge of tyrannosaurid attack strategies to brining [sic] the prey down in order to feed upon it.

New Evidence for Predatory Behavior in Tyrannosaurid Dinosaurs From the Kirtland Formation (Late Cretaceous, Campanian), Northwestern New Mexico (Dalman & Lucas, 2018)

Based off of the orientation of the bite marks on the skull of the ceratopsian (which, though not fully grown, was still respectably large, as indicated by the 2m skull and what were apparently long, well-developed orbital horns), they suggest this ceratopsian was attacked by being brought down to be fed upon.

While one bite mark shows signs of healing (indicating a failed attack), there are multiple other bite marks that show no such signs. While the abstract writes these off as postmortem bite marks, this doesn't really make any sense given that they also state multiple times later in this paper that the ceratopsian skull shows no signs of scavenging (there was no further damage to the skull by the tyrannosaurid's teeth). I think this is indicative of a successful kill.

[dinosauria101]

Just going to deposit my $0.02

For those who may be interested, I've heard the Eotriceratops holotype has bite marks on the left brow horn from an unknown theropod

[creature386]

Where? On Carnivora? A more specific source would be great.

I've found this on Wikipedia:

Three bite marks can be observed above the eye, near the base of the left horn, which were interpreted as traces of scavenging. The squamosal shows at least five episquamosals. Little has been preserved of the parietal bones forming the centre of the neck shield.[1]

en.wikipedia.org/wiki/Eotriceratops

EDIT: Thanks Infinity Blade:

Posterior to the orbit, the grooves—some of which are deep and broad—extend anteroposteriorly. The postorbital forms the smooth posterior border of the orbit. Three shallow pits dorsal to the orbit are interpreted as bite marks.

I'd also like to know where the "scavenging" bit came from. Prehistoric Wildlife might be more accurate than Wikipedia in this particular case.

[dinosauria101]

Jun 17, 2019 0:39:52 GMT 5 creature386 said:

Where? On Carnivora? A more specific source would be great.

It was from Prehistoric Wildlife, which is horrendously unreliable. 
I wasn't able to find anything on Wikipedia, but thanks! Looks like it may be true after all

[Infinity Blade]

Here is the full Eotriceratops description paper. Yes, there are bite marks at the base of the left supraorbital horn core. But unless I glossed over something, they don’t specify anything beyond this: i.e. no mention of what they think made these bite marks, whether this was from scavenging or not, etc.

cyber.sci-hub.tw/MTAuMTEzOS9lMDctMDEx/wu2007.pdf

[Infinity Blade]

A pathologic hadrosaur humerus compared to a normal one.



Edit: this pathologic humerus likely belonged to Hypacrosaurus (original source).

[Infinity Blade]

A specimen of Acrocanthosaurus was apparently bitten by a crocodylomorph. This injury healed.

The left and right maxillae of NCSM 14345 represent the only such elements currently known for Acrocanthosaurus. Although the right maxilla is well-preserved, the left maxilla is missing seven teeth (alveoli 6–12) and a section of the posterior ramus above the fifth alveolus. The tooth of a crocodylomorph was removed from the left maxilla dorsal to the eleventh alveolus. The crocodylomorph tooth was overgrown by a thin layer of bone, suggesting that the event responsible for its emplacement likely occurred well before the death of this individual of Acrocanthosaurus. Lateral surfaces of the maxilla were previously described [1], although internal surfaces were not visible at that time.

Eddy & Clarke, 2011

[Infinity Blade]

Another T. rex with numerous pathologies. Over 50 in the skull alone.

Specimen TE-077 appears to be a mature individual and of average size for its species. Most mature Tyrannosaurids exhibit numerous pathologies from a life of predation, however TE-077 exhibits an unusually high number over the entirety of the skull. The most common forms of pathology exhibited on the skull include punctured bone (bite marks), osteomyelitis (infection seen as swelling in the bone), and healed fractures (previously broken bones). Holes found in the surangular and lower jaws of Tyrannosaurids have been attributed to forms of trichomonosis(1), however further study would need to be conducted to determine causation. In an initial assessment, over 50 pathologies were discovered on the skull of TE-077 alone.*

Most notable in the case of TE-077, is a series of puncture marks (PAG-02), which runs from the angular of the lower jaw upward through the surangular and across the whole of the jugal. It is probable that this represents a severe bite from another Tyrannosaurus during an altercation during the life of the specimen. Even more curious is that the some of the injuries show evidence of healing, while at least one in the center of the surangular appears to be an active infection.

Another notable pathology on the skull of TE-077 is a puncture wound inside the mouth (PAG-01), which runs through the right splenial and continues into the right dentary. While fully healed, two holes remain from the injury, which was most likely caused by something the animal was eating. Acid etched bones, often discovered with Tyrannosaurid specimens, suggests that while eating they swallowed bone and muscle together, so a severe injury from the fractured bone of the prey could potentially inflict such damage. In fact, TE-077, shows an incredible number of such inner mouth injuries including a fractured and healed left coronoid. (PA-48)

Pathologies provide a rare insight into the morphology and ethology of individuals, and can reveal valuable data toward a better understanding of how a species may have looked and behaved. More study will need to be conducted, including comparisons with pathologies on other Tyrannosaurus rex specimens, but TE-077 is likely to contribute considerable information to the study of dinosaur pathology.

*Assessment conducted by Peter Larson, Black Hills Institute of Geological Research

www.theropodaexpeditions.com/portfolios/te-077-pathologic-tyrannosaurus-rex-specimen/

[Infinity Blade]

All the way back in 1987, an Arctodus simus specimen from Indiana has shown evidence of treponemal disease.

sci-hub.tw/10.1038/329061a0

[Infinity Blade]

This is an old one. This mysticete, Diorocetus, likely hit something hard while bottom feeding (like a gray whale) and broke some bones (e.g. a left dentary snapped in half). Because it kept on trying to feed, the wound never got a chance to heal properly. As a result, feeding became impossible and the animal probably starved or became more vulnerable to predators.

vmnhpaleontology.wordpress.com/2009/08/19/left-handed-whale-died-a-painful-death/

[Infinity Blade]

This paper documents cranial pathologies in some woolly rhinoceros specimens, all but one of which are thought to have been from the front horns of other rhinos (Garutt, 1997).

I disagree with this assessment, at least in the case of some of the injuries. The author explicitly claims that two of the pathologies were caused by a conical object, which is reasonable given their circular shape. The front (nasal) horn of a woolly rhino isn't conical at all, it is highly laterally compressed, so there is no way the front horn of a woolly rhinoceros could have caused these pathologies. The back (frontal) horn actually is quite circular in cross section, so if these pathologies were indeed caused by other rhinos, I think the posterior (frontal) horn is more likely to have caused them.

One of the photographed specimens does indeed show injuries that are more elliptical in shape, but even this doesn't match the lateral compression of a woolly rhino's front horn. I'm not sure about the other injuries (particularly from the nasal, orbital, and maxillary joint), but I'm not sure why these also couldn't have been caused by the back horn. In fact, a subsequent publication notes the presence of apical wear on at least one woolly rhinoceros back horn, which suggests use in battles (another back horn shows malformation, which might be the result of trauma), and a cave painting from Chauvet seems to show a woolly rhino using its back horn to block a blow from a rival (Shidlovskiy et al., 2011).

The author seems to assume that the front horn was the primary weapon in the woolly rhinoceros (it is, of course, longer than the back horn). While this might seem reasonable at first glance, it ignores the fact that the cross section of the front horn has a completely different shape from some of the pathologies here, as well as the fact that the blunt tip argues against effective stabbing (Fortelius, 1983). It could be that they still tried to do deliver blows with the nasal horn anyway (as the Chauvet cave painting seems to suggest), even if it wasn't particularly effective for stabbing. In any case, however, I think blocking with the frontal horn – and the wrestling that might have followed immediately afterwards – is likely to have caused injuries on woolly rhinoceros crania.

[Infinity Blade]

Another paper documenting facial scarring in theropods. But this one reveals specimens with a crap ton of facial injuries, and a couple other interesting things. 1) Tyrannosaurs would have positioned their heads next to each other while facing opposite directions, and then lunged sideways to bite, similar to modern Anolis, and 2) evidence for face biting seems to be absent in maniraptoriform theropods (like dromaeosaurids), suggesting they moved away from the basal archosaur/theropod behavior of violent biting to bird-like visual displays with pennaceous feathers.

royaltyrrellmuseum.wpcomstaging.com/2021/09/07/tyrannosaur-facial-scars/


This is the link to the actual paper (which is linked at the end of the article, anyway).

www.cambridge.org/core/journals/paleobiology/article/abs/intraspecific-facial-bite-marks-in-tyrannosaurids-provide-insight-into-sexual-maturity-and-evolution-of-birdlike-intersexual-display/4AC2A6108BC1CE8E849280D9BC4BD9BB