Scheenstia head
Fig. 1. Scheenstia head. Bulverhythe, Bexhill. Scale bar = 25cm.
This specimen was found in blue-grey clay on the beach at Bulverhythe, near Bexhill, by a local fossil collector in May 2008 (Fig. 1). This fish, Scheenstia mantelli, was previously known as Lepidotes mantelli (Lepidotes coming from the Greek, ‘lepidotos’, meaning ‘scaly’).
Between 145 and 125mya, there would have been a variety of fish living in the lakes and rivers of this area, but, by far the most frequently found remains are those of Scheenstia. It could grow to over one metre in length and was covered in thick scales coated with a hard, shiny layer of ganoin. This ‘armour-plating’ would have given Scheenstia protection from some predatory animals and also ensured that its remains survived long enough to become fossilised.
Individual teeth and scales of this fish are very common in local rocks, but specimens with articulated scales are rare. This particular Scheenstia head provides important clues to its feeding habits, as its mouth contains rounded teeth that were probably used for crushing the shells of aquatic molluscs. Scheenstia fossils are often found near freshwater bivalves, such as Neomiodon, which are abundant in the sandstones of the Lower Cretaceous Ashdown and Wadhurst Formations (Hastings Group). Such observations can provide evidence of a small link in the food web of this environment.
The teeth of Scheenstia were continually growing to replace those that were worn or broken, as they still do in fish and reptiles today. With this information, we know that finding a large number of fossil teeth does not necessarily indicate huge populations of particular species. The modern descendants of this ganoid fish include the sturgeon, garfish and bowfin.
The Scheenstia head was prepared by John Dempsey at his ‘Fossil Farm’ workshop and was purchased by Peter Marsden, former curator of the Shipwreck Museum in Hastings Old Town. It is now included in the display of local geology and fossils at the centre.
Theropod footcast
Fig. 2. Theropod dinosaur footcast, Fairlight. Scale bar = 30cm.
This theropod dinosaur footcast was found at Fairlight, where the eastern end of the Lee Ness ledge dips down to beach level (Fig. 2). A plaster cast of the natural footcast was made on 23 June 2008 and, from this, a fibreglass impression was taken.
Footprints and footcasts of the plant-eating Iguanodon are often seen on the bedding planes of this silty sandstone, but those of carnivorous theropods are not so common. Dinosaur footprints can be seen in certain outcrops along the beach from Cliff End to Pevensey Bay – although some of these locations may now be covered by shingle, sand or sea defences. There are even rare examples of trackways, with three or four footprints in sequence.
Dinosaur footprints, footcasts and tracks provide an extremely valuable source of information on the size and behaviour of these animals, and the habitats they occupied. On rocks between Pett Level and Fairlight, the overlapping Iguanodon footprints of varying sizes indicate that they moved in herds or family groups. Other evidence, such as associated ripple-marks, suggests that these animals may have been grazing on the shore of a lake or river estuary. Sometimes, even their possible food source – plants such as horsetails (Equisetites) – can be seen as fossils in nearby rocks.
While the fossilised bones of a foot will give its structure, a preserved footprint or footcast will show the actual shape of a living dinosaur’s foot. In fact, the shape of a footprint can also tell us something of the animal’s mobility. The bulbous heel and fleshy pads of an Iguanodon footprint suggest a large, slow-moving animal, such as a plant eater, whereas the narrow, bird-like foot impressions of a theropod indicate a fast-moving hunter.
Occasionally, both herbivore and carnivore footprints can be seen on the same bedding plane, giving important clues as to their ratio in the area. Here we might visualise a lakeside scene 138mya – with a theropod stalking a group of Iguanodon.
Conifer cone
Fig. 3. Conifer cone from Fairlight. Scale bar = 20cm.
In April 2008, work was in progress on the Fairlight landslip sea defences, when Jackie Skipper discovered this unusually large fir cone in a block of sandstone (Fig. 3). Jackie, a senior geologist at the Natural History Museum, was employed as the site geologist by Rother District Council. The cone was later cut from the rock and is now awaiting formal identification by Paul Kenrick, a Natural History Museum plant specialist.
Because plants are particularly sensitive to climatic and environmental conditions, their fossils can provide very useful information. Plant remains found in Lower Cretaceous sediments have shown that the seasons ranged from warm and wet (monsoonal) to hot and dry, resulting in vegetation fires and carbonised plant material.
The low-lying flood-plains, deltas and lakesides provided ideal environments for the pteridophytes (ferns, horsetails and clubmosses), which reproduced by means of spores, but the gymnosperms (‘naked seeds’), which include the conifers, would have grown on slightly higher, drier ground.
Complete specimens are rarely found, as most plants soon decomposed in the humid conditions or were washed away and reduced to fragments in turbulent waters. The few that have been preserved intact were probably covered quite rapidly by sediment in calm water.
For many millions of years, the gymnosperms, with their tough stems and leaves, dominated the land, but it was during the Lower Cretaceous that the first true flowering plants, or angiosperms (‘enclosed seeds’), began to spread and diversify.
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