Keen-eyed Pupil Spots Tiny Dinosaur Bone

A Japanese schoolboy on an outing with his family to a mining museum has discovered the toe-bone of a dinosaur, most likely a member of the theropod group of dinosaurs and the bone may represent a species that is new to science.  The tiny fossil, it measures just three centimetres in length, was found by Takato Sasaki, who was on a visit to the Kuji Amber Museum in Kuji, Iwate Prefecture, the north-eastern part of Honshu island (Japan).

Kuji Amber Museum

The Kuji Amber Museum is the only museum of its kind in Japan, amber can be collected in this area, the fossilised tree resin dates from approximately fifty million years ago (Palaeogene geological period) to as old as approximately one hundred million years ago (Cretaceous geological period).  The fossil, although very small and representing just a single toe bone has been tentatively dated to around eighty-five million years ago (Santonian faunal stage of the Late Cretaceous).  The fossil was found last May, it has been identified as a pedal phalange, a toe bone from a bipedal, fast-running dinosaur that may have been between one and two metres tall.  The height of the dinosaur can be estimated by comparing the size of this toe bone with the pedal phalanges of more complete specimens of bipedal dinosaur where more of the skeleton has been excavated.

Dinosaur Toe Bone

Researchers such as Professor Ren Hirayama (Waseda University), have stated that the bone came from the left hind foot of a member of the Coelurosauria dinosaur family.  The Coelurosauria clade of dinosaurs is an exceptionally diverse group of theropod dinosaurs. It includes the ornithomimids, the tyrannosaurs, Compsognathidae and the raptors such as the dromaeosaurs.  Dinosaur fossils are extremely rare in Japan.  Those that are found tend to be very fragmentary, for example, a distinctive, tooth root found earlier this year suggests evidence of horned dinosaurs living on the land mass that we now know as Japan in the Late Cretaceous.

To read more about the fossil evidence suggesting horned dinosaurs once lived on the land we now know as Japan: Japan’s First Horned Dinosaur.

A couple of years ago, Japanese scientists found a huge thigh bone (femur) of a dinosaur.  This suggests that there may have been dinosaurs very similar to titanosaurs living in this part of the world back in the latter stages of the Mesozoic.

To read an article on the discovery of the huge femur: Huge Femur Fossil Found in Japan.

Professor Ren Hirahama commented:

“It is uncommon that a toe bone, which is easily worn away, was found in such good condition.”

The bone is not much bigger than the schoolboy’s little finger, it measures just three centimetres in length and just about one centimetre in diameter at its widest part.  Given that the scientists have only a single bone to study, they can’t say much more about this dinosaur, it is not possible to identify the genus, but it does show that there were fleet-footed relatives of Tyrannosaurus rex living in Japan during the Late Cretaceous.

Eroded Out of Older Sediments

The bone may have been re-deposited having been eroded out of older sediments and become mixed up with the amber bearing strata, although if it had been transported a significant distance, the palaeontologists would have expected the tiny fossil bone to show more signs of erosion than it actually does.

High school student Takato Saski, is said to be very excited about his discovery, the tiny specimen was found at an amber mine site on the museum’s premises.  Describing the moment when he first saw the object, Takato stated:

“At first I thought it was just a small branch, but it was more amazing than that”.

Young people have two major advantages when it comes to finding fossils.  Firstly, they tend to be shorter than adults, this means that they are closer to ground and since fossils tend to be found on the ground, they are closer to where the action is – from a palaeontological perspective.  In addition, their young eyes generally tend to be more acute and a better sense of vision can help young people spot small objects, even tiny dinosaur toe bones.

For further information about fossil hunting and dinosaurs: Contact Everything Dinosaur.

Scientists are hopeful that news about this rare find will encourage more sharp-eyed visitors to the museum.  Perhaps more fossilised fragments will come to light and these fossils can help palaeontologists to understand the diversity of the Dinosauria in this part of the world towards the end of the Cretaceous.