Was Eubrontes Track Maker Gregarious? (free pdf)

[Ben Creisler <bcreisler@gmail.com>]

Ben Creisler
bcreisler@gmail.com


A new paper:

Patrick R. Getty, Laurel Hardy and Andrew M. Bush (2015)
Was the Eubrontes Track Maker Gregarious? Testing the Herding
Hypothesis at Powder Hill Dinosaur Park, Middlefield, Connecticut.
Bulletin of the Peabody Museum of Natural History 56 (1):  95-106
http://www.bioone.org/doi/abs/10.3374/014.056.0109
Free pdf here:
http://www.researchgate.net/profile/Patrick_Gonsoulin-Getty



The theropod footprint taxon Eubrontes is common in Early Jurassic
rocks of the Hartford Basin. Aligned Eubrontes trackways at one site
in Holyoke, Massachusetts, have led to the hypothesis that the track
makers were gregarious; however, trackways are not aligned at several
other sites. To test the gregariousness hypothesis, we measured
trackway orientations at Powder Hill Dinosaur Park in Middlefield,
Connecticut, where exposed rocks were deposited in an ephemeral lake
environment, and compared these orientations to those of two
additional track sites from similar sedimentary facies. The Eubrontes
trackways produced in the ephemeral lake environments have no
preferred orientation and provide no evidence of gregarious behavior.
We suggest that the alignment of tracks in Holyoke reflects behavior
in response to environmental settings rather than group behavior.
Trackways may be aligned next to large, permanent lakes because of
shoreline-parallel travel, but random orientations characterize other
habitats. This study underscores the value of examining track sites
from different paleoenvironments when inferring dinosaur behavior.