Hylonomus Returns Home
Oldest Reptile Fossil Returns to Nova Scotia
The coal deposits of Nova Scotia, laid down in the Carboniferous Geological period, some 310 million years ago, preserve a remarkable fossil record of the swamps and forests of this ancient time in Earth’s history. Giant clubmosses and horsetails shared the landscape with strange tree-like Sigillaria and tall Lepidodendrons. The climate was equatorial and the fossils at perhaps the most important site in Nova Scotia (Joggins, 150 miles north-west of Halifax) also preserve evidence of the animals that lived in this swampy domain.
More than 190 fossil skeletons of small amphibians and reptiles have been discovered at the Joggins site. The Joggins cliffs were declared a World Heritage site by UNESCO in 2008, such is their importance to science. Now one of the best preserved fossils of a tiny reptile, no more than 20 centimetres long is being returned to Canada for the first time since it was sent to London, more than a century ago.
The fossil is of Hylonomus lyelli an insect eating reptile, that is believed to be one of the first of its kind. Its head was proportionally much smaller than the amphibians from which it was descended. However, the structure of the skull shows a significant advance over an amphibian skull as it allowed more space for the attachment of stronger jaw muscles.
This fossil was uncovered by Nova Scotian geologist John William Dawson in 1859 but was handed over to the British Museum around the turn of the century. The British Museum is now known as the Natural History Museum. The fossil is going to be on display at the Joggins Fossil Centre for the next six months.
The Joggins Fossil Centre’s chief palaeontologist Melissa Grey commented:
“If you look closely, you can see elements that you would recognise. Bits of the jaw with teeth and the backbone and the tail and some of the legs as well.”
The fossil is so delicate and precious, it had to be delivered by hand. Such a cargo cannot be trusted to even the most conscientious of courier firms. A number of small reptile and amphibian fossils have been discovered at the site, many have been recovered from the tree-sized stumps of large Carboniferous plants. How or why these creatures ended up preserved in the remains of ancient plants is a mystery.
A number of theories have been proposed, for example these small vertebrates may have made such tree stumps their homes. Or perhaps small creatures fell into the rotten stumps and found themselves stuck, unable to crawl out again – an example of a natural “bottle trap”.
Whatever the explanation, these fossils are very important to scientists as they attempt to piece together the story of how vertebrates came to conquer the land.
“This is the world’s oldest known fossil reptile. So it is very important to our understanding of vertebrate life, animals with a backbone and that includes us.”
The fossil will form part of a special display and will be on show until October 31st.
For models and replicas of prehistoric animals from the Palaeozoic: CollectA Prehistoric Life Models.