This is a very large toe bone from a “big bone headed” dinosaur
of the Late Cretaceous.
The Pachycephalosauria, meaning thick headed lizards,
is a family of dinoaurs from Order Ornithischia that includes such
well known genera as Pachycephalosaurus, Stegoceras, Stygimoloch,
and Dracorex. Most lived during the Late Cretaceous Period in what
is now North America and Asia. They probably traveled in herds,
were bipedal, and herbivorous/omnivorous animals characterized by
thick skulls. Some had a domed skull roof that was several inches
thick and bearing nodes.
function of the thickened skull roof has been heavily debated. It
has been frequently postulated that individuals may have rammed
each other head-on, as do modern-day mountain goats and musk oxen.
It is also suggested that pachycephalosaurs could make their head,
neck, and body horizontally straight, in order to transmit stress
during ramming. The fossil record suggests that the earliest pachycephalosaurs
arose in Asia about 85 million years ago, and were relatively small.
Early genera ostensibly crossed the land bridge that during the
Cretaceous times connected Asia and North America. North American
genera evolved to be larger than those in Asia.
Recently the Fossil Mall associates purchased a
large lot of dinosaur, reptile and mammal material from our primary
collector. He lives in Montana and has over fifteen years of field
collecting experience. Ten days were spent in obtaining this lot.
The fossils were discovered in Cretaceous stream channel deposits.
Some were surface collected as float; many were partially eroded
out of the low-lying surrounding gullies and bad lands. The process
continued upon his return home. There the specimens had to be cleaned
and identified, a long and tedious process that lasted many days.
Upon completion, all the specimens were photographed and submitted
to us at the Fossil Mall for consideration of purchase. Needless
to say, we bought the whole batch.
A word regarding the legality of these fossils.
Our provider only collects on private ranch and farmlands of Montana
and South Dakota. His relationships with these landowners have been
cultivated over many years of door knocking and often difficult