The discovery of an embryonic dinosaur bonebed
from China is the oldest such occurrence in the fossil record.
Only about one square metre of the bonebed
has been excavated to date, but this small area also yielded pieces of eggshell, the oldest known for any terrestrial vertebrate.
30 groups focus on a specific section that is known to contain juvenile centrosaurus fossils.
New research since 1987 by one of the editors (Brunswig) has established a deposition date for the 'bonebed
' around 11 000 BP and that the mammoths (MNI: 14 in the sample) represent accumulated kills in several incidents; oxygen isotope analysis on the teeth confirms that the mammoths were killed at different seasons, probably in ambushes in a gully of the Colorado piedmont; analysis of butchery marks is interpreted as 'serially episodic processing' (p.
A great quantity of non-articulated shells corresponding to indeterminate bivalves occur in the layers at the base of this bonebed
, and a great accumulation of nearly complete linear leaves of conifers occurs in the grey laminated clays located at the top.
Taphonomy and paleoecology of a bonebed
from the Prince Creek Formation, North Slope, Alaska.
The Bairds concentrated on Carboniferous formations but made their most significant discovery in rocks regarded as Lower Permian: a bonebed
in the Nineveh Limestone at Clark Hill in Monroe County, Ohio (Berman 1978).
"Data from this mega bonebed
provide pretty clear evidence that these and other dinosaurs were routinely wiped out by catastrophic tropical storms that flooded what was once a coastal lowland here in Alberta, 76 million years ago," the Globe and Mail quoted David Eberth, a senior research scientist at the museum, the lead author on the study and one of the book's three editors, as saying.
The books draw on research conducted over two decades, made possible because of the discovery of a densely packed bonebed
near Grande Prairie, Alberta, Canada, which yielded a new species of horned dinosaur, the ceratopsian.
Kentriodon obscurus (Kellogg, 1931), a fossil dolphin (Mammalia: Kentriodontidae) from the Miocene Sharktooth Hill Bonebed
The new dinosaur was discovered in a bonebed
on private land located along the Milk River in North Central Montana.