All about dinosaurs, fossils and prehistoric animals by Everything Dinosaur team members.
24 08, 2007

Ancient Crocodile Skull found in Dorset

By | August 24th, 2007|Dinosaur and Prehistoric Animal News Stories, Main Page|0 Comments

Cretaceous Crocodile unearthed in Dorset

The beautifully preserved skull of an ancient crocodile discovered on the Dorset coast has just gone on display at the Swanage Museum and Heritage Centre.  The 58cm skull is of a Goniopholis, a broad snouted semi-aquatic crocodilian the lived in the early Cretaceous, sharing the riverbanks with herds of Iguanodon.

The skull was found in April by Richard Edmonds, the Earth Science Manager for the Jurassic Coast World Heritage site, whilst inspecting a cliff fall at Swanage on the Dorset shoreline.  The post cranial elements were lying in the rubble with the rest of the skull retained with the cliff.  Working with local fossil hunters the skull was carefully removed, cleaned and will be on display for a few weeks at the local museum.  Scientists from Bristol University and the London museum of Natural History will then take the specimen away for further study, to see if this find represents a new species of ancient crocodile.

The Goniopholis Skull

Ancient DorsetCrocodile

Picture courtesy of 24hourmuseum.org.uk

A number of species of Goniopholis are known from Upper Jurassic and Lower Cretaceous sediments.  These animals are classified in the mesoeucrocodylia family, these ancient crocodiles ranged in size from 2-4 metres in length and are believed to be the direct ancestors of extant crocodilians.  The skull could have belonged to a G. crassidens.  Goniopholis crassidens was the first of this genus to be named and described.  It was Richard Owen who was given the task of classifying this animal, he completed this paper in 1841.  At around this time, Richard was beginning to comprehend that the huge extinct reptiles – Megalosaurus, Iguanodon and Hylaeosaurus were so different from the crocodiles, pterosaurs and marine reptiles that they deserved to be put into their own distinct order.  Richard Owen (along with many of his contemporaries) was beginning to recognise that these extinct animals needed their own order, the thought process that led to the naming of the Dinosaurs had begun!

Click here to read about the rivalry between scientists at the time the word Dinosauria was first used:  What’s in a name – the Classification of Dinosauria

24 08, 2007

How did the Silurian Period get its Name?

By | August 24th, 2007|Geology, Main Page, Palaeontological articles|0 Comments

Why is the Silurian called the Silurian?

Recently we took a small party to some locations we know in the county of Shropshire where you can find fossils of brachipods, bivalves, coral and such like. Shropshire’s geology is strongly associated with the Silurian period (it lasted from approximately 435mya to 410 mya), indeed two of the epochs within the Silurian are named from places in the county – the Ludlow and Wenlockian epochs.  However, geologists in North America have different terms for rocks of this age from the Silurian (the Lockportian and the Tonawandan).

The Silurian marks a period of sea level rises (called marine transgressions), much of the county was covered in warm, shallow seas, during this time and marine life flourished.  The beginning of the Silurian (Silurian/Ordovician boundary) is marked by a major extinction event but by the time the rocks that form Wenlock Edge were laid down life was once again flourishing with jawed fish such as the placoderms and acanthodians beginning to diversify.  The arthropods continued to dominate and were the top predators  during this period.   The first corals were forming in these shallow seas, made by the now extinct rugose and tabulate corals.

Whilst on our fossil hunting trip we were asked how the Silurian got its name.  The Silurian was named by Sir Roderick Murchison, the wealthy Scottish aristocrat.  Sir Roderick had thought in the wars against Napoleon but when these ended he turned his attention to the embryonic science of geology.  Encouraged by friends such as the Reverend William Buckland (the very same William Buckland who named and described the very first dinosaur – Megalosaurus); he explored the fossil-bearing strata of south Wales and Shropshire.  Being independently wealthy Sir Roderick was able to mount expeditions to explore the geology of Europe and his connections soon saw him elected to the London Geological Society.

Sir Roderick named the rock strata that made up the chronological succession of fossils the Silurian after an ancient Welsh Celtic tribe called the Silures.  At the time, his friend and colleague Adam Sedgwick (Professor of Geology at Cambridge University) had just named the much earlier rock strata where the first great abundance of fossils had been found – the Cambrian, after another ancient Welsh tribe.

Silurian strata shows the first signs of the colonisation of the land with the establishment of primitive vascular plants such as Cooksonia. During this time the first arthropods ventured onto land.

Load More Posts