Judith River Formation tooth marks show smaller tyrannosaurid feeding on larger tyrannosaurid (free pdf)

[Ben Creisler]

Ben Creisler

bcre...@gmail.com

A new paper:

Free pdf:

Josephine Nielsen, Denver Fowler, Taia Wyenberg-Henzler, Aase Roland Jacobsen & Christof Pearce (2026)
Investigating Size-Asymmetric Feeding Among Tyrannosaurids Using Tooth Marks on a Metatarsal from the Judith River Formation, Montana, USA
Evolving Earth 100107
doi: https://doi.org/10.1016/j.eve.2026.100107
https://www.sciencedirect.com/science/article/pii/S2950117226000038


Highlights

First detailed application of the Category-Modifier (CM) system to describe tyrannosaurid bite marks on a theropod metatarsal.
3D surface modelling and quantitative analysis revealed 16 distinct tooth marks, indicating multiple bite marks.
Evidence supports size-asymmetric feeding behaviour between tyrannosaurids, involving a smaller tyrannosaurid feeding on a larger tyrannosaurid.
BDM 124 serves as a new data point of trophic interaction among Campanian tyrannosaurids of the Judith River Formation

Abstract

The Judith River Formation in Montana, USA, is a key Campanian-aged sedimentary package, with a rich fossil assemblage, including multiple tyrannosaurid taxa. This study documents BDM 124, a partial left II metatarsal exhibiting multiple tooth marks consistent with tyrannosaurid feeding activity. Using the Category-Modifier (CM) classification system and high-resolution 3D surface scanning, 16 distinct marks were systematically characterized. Morphometric analyses and Non-metric Multidimensional Scaling (NMDS) revealed grouping patterns suggestive of size-asymmetric feeding behavior. The small size and spacing of the marks indicate that they were produced by a small tyrannosaurid, most likely scavenging on the carcass of a significantly larger conspecific or closely related taxon. The absence of healing, mark placement on the metatarsal, and their morphology collectively suggest a late-stage carcass consumption. The study contributes a new data point to our understanding of trophic dynamics and interactions among Late Cretaceous tyrannosaurids, highlighting the value of systematic methodologies for interpreting tooth marks.

====

[Denver Fowler]

I appreciate you (somehow!?!) getting this paper on the DML so quickly, but people please be aware that this is the pre-proof and we have a few small non-scientific errors in there to correct. There are some grammar etc, but, for example, some references are missing from the end. The general content should be fine, but I'd still prefer the journal to have waited. It is slightly embarrassing that the journal puts out a "pre-proof" online. What, indeed, is the point of a proof if they put out the "pre-proof" stage?

----------------------------------
Denver Fowler, Ph.D
Curator, Dinosaur Museum @ Dickinson Museums Center
& Fowler Paleontology & Geology Consulting
df9...@yahoo.co.uk
http://www.denverfowler.com
https://www.facebook.com/Fowler-Paleo-continuing-the-dinosaur-research-and-fieldwork-of-Dr-Horner-230141317002543/
-----------------------------------

--
You received this message because you are subscribed to the Google Groups "Dinosaur Mailing Group" group.
To unsubscribe from this group and stop receiving emails from it, send an email to DinosaurMailingG...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/DinosaurMailingGroup/CAMR9O1L3LfQu8WKxX0aK%2BAQVTwpJa7dDATP7c%2BSkYi72f7dLfw%40mail.gmail.com.

[Mickey Mortimer]

Whole sections show up as gibberish to me, although copy/pasting results in the correct letters and order but wrong spacing, like the Acknowledgements- "W e tha nk Ro d a nd B rent O lso n w ho c o llec ted the spec im en o n the 1 3th o f Septem ber 2 0 1 2 ,
a nd a lso Ca ro l O lso n w ho do na ted the spec im en to B D M . Tha nks a lso to the elec tro nic s
tec hnic ia n at Aa rhu s U niversity, Christia n Nederga a rd, fo r pro viding the print o f the 3D

m o del. The a u tho rs rec eived no externa l fu nding fo r this w o rk."

But in Acrobat Reader, that starts as "Tb>>^kh>>O ... etc.

Mickey Mortimer