RESEARCHERS have unearthed an enormous fossil rabbit skeleton on Minorca.
A recent study published in the Journal of Vertebrate Paleontology highlights this new find. This massive rabbit, aptly named the Minorcan King of the Rabbits (Nuralagus rex), weighed in at 12 kg (26.4 lbs) - approximately ten times the size of its extinct mainland cousin (Alilepus sp.) and six times the size of the living European rabbit, Oryctolagus cuniculus.
When lead author Dr. Josep Quintana from the Institut de Paleontologia Miquel Crusafont Museum (now Institut Català de Paleontologia) realized what he had discovered, he was awestruck. When I found the first bone I was 19 years old, I was not aware what this bone represented. I thought it was a bone of the giant Minorcan turtle, he said.
The rabbit king lived approximately 3-5 million years ago and may be one of the oldest known cases of the island rule in mammals. Simply put, the island rule states that when on islands, big animals will get smaller and small animals will get bigger. This size change on islands may be due to reduced quantities of food or lack of mainland predators. On Minorca, Nuralagus rex lived with few other vertebrate species. Some of its neighbors included a bat (Rhinolophus cf. grivensis), a large dormouse (Muscardinus cyclopeus), and the above-mentioned giant tortoise (Cherirogaster gymnesica). In the case of N. rex, the lack of predators allowed this rabbit to reach a giant size.
Quintana and colleagues found that this giant rabbit had also lost its ability to hop. The long springy spine of a mainland rabbit is lost in N. rex, replaced by a short, stiff spine that would make jumping difficult. I think that N. rex would be a rather clumsy rabbit walking. Imagine a beaver out of water, said Quintana.