Propanoplosaurus, nodosaur hatchling natural mold from Maryland

[bh480@scn.org]

From: Ben Creisler
bh480@scn.org

In the new issue of Journal of Paleontology:

Ray Stanford, David B. Weishampel and Valerie B. Deleon 
(2011)
The First Hatchling Dinosaur Reported from the Eastern 
United States: Propanoplosaurus marylandicus (Dinosauria: 
Ankylosauria) from the Early Cretaceous of Maryland, 
U.S.A.
Journal of Paleontology 85(5):916-924.
http://www.bioone.org/doi/abs/10.1666/10-113.1
Abstract
Abundant and diverse dinosaur footprints have been 
discovered recently on bedding surfaces of the Lower 
Cretaceous Patuxent Formation of Maryland and Virginia. 
Found along with those ichnofossils is a fossil preserved 
partially as natural casts and partially as natural molds 
of a baby nodosaurid ankylosaur so small as to justify 
interpreting it as a hatchling. Despite the rather 
unusual type of preservation, the find is properly termed 
a body fossil and not an ichnite, per se, because it 
records not the action of an organism, but the body form 
and bone structure (including partial articulation) of a 
dinosaur. We here name it Propanoplosaurus marylandicus 
and provide a description of its diagnostic 
characteristics. Although actual skeletal remains 
referable to P. marylandicus have not been found in the 
Patuxent Formation, other nodosaurids recognized from 
skeletal remains are known from both the Lower and Upper 
Cretaceous strata of the Western Interior of North 
America and Europe. P. marylandicus represents the only 
diagnostic nodosaurid from the Early Cretaceous of the 
eastern U.S.A., provides information on growth patterns 
among nodosaurids, and is the first direct evidence of a 
dinosaur hatchling and, deductively, nesting, on the 
entire eastern
seaboard