There are several gaps in the fossil record- periods of time when nothing is known of a particular group and scientists have to wonder about evolutionary developments in that period. One classic example is ‘Romer’s Gap’ named after the influential American palaeontologist Alfred Sherwood Romer, whose special study was the evolution of primitive terrestrial vertebrates from the ancestral fish. This is a 30 million year period between the late Devonian and into the early Carboniferous, during which time the clumsy early swimming tetrapods had developed into a wide range of amphibians and amphibian-like animals, many of which pursued a land-lrving existence. Very few fossils exist from this period of time, possibly because soil or climate conditions did not allow any to form. The recent discovery of Pec/erpes in Scotland, along with the slightly later Whatcheerta in America and another called Ossmodus in Queensland. Australia – all three from Romer’s Gap – is beginning to shed light into this dark area of vertebrate evolution. Animatronic Dinosaur
Until the discovery of Pederpes, Casineria was the earliest-known animal with a terrestrially adapted skeleton. It is so advanced that it is regarded as being on the line that led to the amniotes – the animals that laid eggs on land. Its small size – most of which is tail – suggests that the land¬living animals did not evolve from the big aquatic Devonian terrapods, but from much smaller relatives. It probably lived like a modern salamander, scuttling about in moist undergrowth, feeding on the insect life that abounded in the early land vegetation. Walking Dinosaur Costume
Features: The most obvious feature of the single skeleton of Casineria that has been found is the clear adaptation to land-living. The backbone is much stronger than in any of the water-dwelling Devonian amphibians, and the humerus is weight-bearing like that of a reptile. The five fingers and toes have notches that must have held tendons, indicating that they could be curled – an adaptation to walking over rough terrain. Unfortunately the skeleton lacks the head and tail.
Left: The name, a latinized version of ” Cheese Bay”, is a direct reference to the site near Edinburgh. Scotland, where Gasmena was found.