July 11, 2008 -- An Iguanodon feasting on ferns died, perhaps after becoming stuck in a marshy floodplain, and was then consumed by an enormous dinosaur with huge claws that left behind a few of its teeth, suggests a new study on animal and plant remains excavated in southern England.
The findings, which are described in a paper accepted for publication in the journal Cretaceous Research, even indicate what happened in the region well before the Iguanodon was born, as well as what took place after the hungry carnivore, Baryonyx, enjoyed its Iguanodon feast.
"Our study is in that regard remarkable, as it is a comprehensive, multidisciplinary study of the sedimentology and all the different microfossil groups present in the dinosaur-bearing bed," co-author Susanne Feist-Burkhardt told Discovery News.
She added, "Usually you will find a publication each about one fossil group and it is difficult to fit the information together into a single coherent picture."
That was not the case for this set of finds, dating to around 130,000,000 years ago and excavated at the Smokejacks Brickworks in Ockley, Surrey. The animal remains, along with pollen grains from some of the world's earliest flowering plants, spores, megaspores, green algae and shellfish, all paint a picture of certain events and what the environment there was like during the Early Cretaceous.
The pollen and spores indicate that many thousands of years before the Iguanodon was born, cone-bearing trees and big shrubs dominated the site. As time went on, liverworts and various types of ferns and mosses emerged. Dense fern undergrowth was then dotted here and there with the early flowers, all belonging to the genus Retimonocolpites.
When the Iguanodon came on the scene, this plant eater had its pick of edibles.
"Iguanodon was a large herbivorous animal and probably fed on all available vegetation, the conifers as well as the leafy and more nutritious pteridophytes (mosses and ferns)," explained Feist-Burkhardt, a researcher in palynology at the Natural History Museum in London. "The Iguanodon probably moved out onto the exposed floodplain for the only available freshwater during the dry season and fed on the available plants."
She said numerous, extremely well-preserved ostracods, a shellfish commonly known as "seed shrimp," were preserved in the sediment next to the Iguanodon's remains. She even thinks the decaying dino's body created a "micro-environment" that helped to prevent the calcium carbonate in the shells from dissolving.
Two Baryonyx teeth were also found near the Iguanodon, which she said might indicate "Baryonyx was scavenging the Iguanodon carcass." Other studies show that this carnivore ate a lot of fish, so it's possible the long-snouted meat eater with big, sharp claws stumbled upon the Iguanodon body while gulping down fish.
The manner in which the Iguanodon's body decomposed suggests the herbivorous dinosaur may have died in a standing position, or had its body fall in that way, with its head resting where the shallow pool of freshwater met the sediment surface. Green algae, enriched by nutrients in the dead dino's flesh, then bloomed brightly around it.
David Batten, honorary professor of paleontology at the University of Manchester, has also conducted studies on the plant microfossils at the Smokejacks Brickworks site, as well as surrounding regions.
He told Discovery News that the new study presents findings that "are consistent with previous observations."
The Surrey finds add to the evidence that England was once a dinosaur hot spot. One 95-mile-long section of the nearby Dorset coast has so many ancient animal and plant remains that locals now refer to it as The Jurassic Coast.
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