New Basal Sauropod Discovered in South America

Fossils of a basal sauropod are helping palaeontologists to revise the Dinosauria cladogram.

The Order Dinosauria is divided into two fundamental groups the Saurischia (lizard-hipped dinosaurs) and the Ornithischia (bird-hipped dinosaurs).  This classification was established in the 19th century and, although the terminology is a little confusing the basic cladogram of dinosaur relationships has remained largely unchanged.

Dinosauria Classification

Dinosaurs are classified into different groups or families according to anatomical features that their skeletons reveal.  If two dinosaur fossils are shown to have very similar anatomical features it is likely that they will be classified together, whereas a third dinosaur fossil which demonstrates different features will be placed further away on the dinosaur family tree.  The two basic groups – Ornithischia and Saurischia are distinguished by having markedly different hip structures.  This is of course, greatly simplified, there are in fact about a dozen characteristics that distinguish dinosaurs from other reptiles.

The terminology used may not have changed since the days of Owen and Huxley but our greater understanding of dinosaur taxonomy has led to many scientists suggesting a re-think when it comes to classifying dinosaurs.  For example, the ornithischian dinosaurs, the bird-hipped dinosaurs are not, as the name would suggest, as closely related to birds as the Saurischia.

Dinosaur Evolution

How dinosaurs first evolved and then developed into their myriad forms has been a question that has long puzzled palaeontologists.  The lack of fossil evidence has frustrated many a researcher, the rise of the dinosaurs and their evolution into such diverse forms remains a mystery.  It is difficult to identify basal forms and work out the evolution of certain types of dinosaur with so little evidence preserved in the fossil record.

However, a paper published by a team of scientists from the National University of San Juan, Argentina, in the prestigious scientific Internet journal PlosOne.org throws new light on the evolution of plant-eating dinosaurs.  In particular, the paper, which discusses a newly discovered South American dinosaur provides an insight into the evolution of the sauropods, the largest land animals of all time.

Basal Sauropod

South America is regarded as the cradle of dinosaur evolution.  As far as scientists are able to deduce; the dinosaur dynasty began with the small, agile meat-eaters in South America, but they may have existed in other parts of Pangaea.  Perhaps the most primitive of all the dinosaurs Eoraptor (name means dawn thief), was found in Triassic deposits of the Ischigualasto Basin in north-western Argentina.  This small, bipedal dinosaur had serrated teeth indicating that it was a carnivore.

The fossils of this particular dinosaur have been dated to approximately 230 million years ago (Carnian faunal stage), making it one of the earliest known of all dinosaurs.  It is believed that it was from these bipedal theropods that the dinosaur lineage developed.  However, how the dinosaurs gradually evolved plant-eating forms from carnivores remains unclear.

This new paper, a study on a disarticulated almost 45% complete dinosaur found in the Ischigualasto Basin, may provide a fresh perspective on this mystery.  The fossils, unearthed three years ago are that of an omnivore, an animal evolving from a meat-eating diet to a herbivorous one.  These fossilised bones may belong to an ancestor of the giant saurischian sauropods, some of the biggest animals ever to live on land.

Panphagia protos

This new species of dinosaur has been named Panphagia protos (name means first-everything eater), it is similar to Eoraptor although the fossils indicate that this animal may have been up to 3 metres long.  The remains are believed to be that of a juvenile so determining the maximum size of this beast is a little difficult.

Although the bones of this animal had been studied for a while, leading the researchers to conclude that this animal was a bipedal, carnivore like Eoraptor, the team had to re-visit their research when close examination of the dentition (the teeth) indicated that these fossils could represent an animal in a transitional state between evolving from a meat-eater into a fully herbivorous dinosaur.

Museum Director Oscar Alcober commented that it took the team many months to fully appreciate that the newly discovered species represented a transitional form.  The teeth of this dinosaur are different from Eoraptor, much straighter, lacking a curvature and quite sharp indicating that this animal may have been an omnivore.  Analysis of the cervical vertebrae, (neck bones) indicate that the neck was beginning to lengthen, an adaptation for eating plants, permitting these animals to consume large amounts of food from a stationary position and to reach up into higher branches to graze.

Oscar Alcober stated that Panphagia was a dinosaur “in the full process of evolution.”

Bones Recovered from the Site

The bones shown in white in the images indicate the ones recovered from the site, the ones in light grey and dark grey are missing.  Panphagia has been classed as a basal sauropodomorph an ancestor of the huge sauropods of the Jurassic and Cretaceous and dated to approximately 230 million years ago.  It seems to be closely related to another very early plant-eating dinosaur discovered in South America – Saturnalia.  Although these two dinosaurs were relatively small, perhaps no bigger than 3 metres long, they are classed as early members of the Sauropodomorpha and indicate the shape of things to come for some members of the Saurischia.

Everything Dinosaur stocks a range of basal dinosaur figures and models, to view the dinosaurs and prehistoric animal models available: Dinosaurs and Prehistoric Animal Models.

Return to the Carboniferous – take a trip to North Wales

The fossilised remains of gigantic tree-like plants are going on display at the Wrexham Museum as part of an exhibition entitled “From Coals to Carnations”.  The prehistoric fossilised trees, some of which were upwards of 40 metres tall once formed part of a dense swampland in which huge insects and the first reptiles thrived.

Fossilised Trees

The fossilised trees were first uncovered during overcast mining works on the site of a former steel mill near Wrexham in 2003.  The actual site is at the village of Brymbo, just a few miles to the north of Wrexham.  The fossilised finds demonstrate that approximately 300 million years ago the land that was to eventually form Wales was much closer the equator than today and made up part of a super continent called Laurentia that covered much of the Western Hemisphere.

Geologists have been working on the site since its discovery, but work was accelerated from 2006 as the exposed fossils formed from mudstone, began to be weathered and there were some concerns about losing these rare fossils.  More than 20 individual specimens have been identified, a number of which are going on display to the public for the first time at the Wrexham Museum.  These ancient plants date back from before the time of the dinosaurs, and before flowering plants.  They are the trunks of giant clubmosses like Lepidodendron.  The scientific name for clubmosses are Lycopsids, a number of clubmoss genera still survive today, but they tend to be very small, no match for their huge ancestors.

A Carboniferous Forest Scene

A museum exhibit showing a typical Carboniferous habitat.  Huge invertebrates such as Arthropleura roamed the forest floor.

Picture credit: Everything Dinosaur

Coal Deposits

As wood and other plant material was compressed and decayed it went onto form coal deposits.  The Welsh coal fields took approximately 20 million years to form, since the Industrial Revolution about 200 years ago, most of these coal fields have been exhausted.  A team of geologists helped oversee the preservation of the fossils, which had all been found at a site just 50 metres in length.  This land is designated for new housing and light industry, but the developer Parkhill Estates, after discussions with local lobbyists decided that they wanted to try to preserve as many of the fossil specimens as possible.

The Wrexham Museum exhibition will provide visitors with a rare insight into the area’s prehistoric past.

To view replicas and figures of animals from the Palaeozoic and other extinct creatures: CollectA Prehistoric Life Replicas.

Road Builders in Peru Discover Fossils

Peruvian construction workers have uncovered an array of body and trace fossils dating back to the age of the dinosaurs as they worked on a new road, one of the discoveries is a dinosaur trackway.  As well as dinosaur fossils, including some really well preserved footprints, the road workers found fossils of crocodiles, pterosaurs, primitive tortoises and remains of extinct species of fish.

Palaeontologists who have been called in to study the site have revealed that the remains of at least a dozen animals have been found, the sediments date back to the Early Cretaceous and have been dated to approximately 120 million years ago (Aptian faunal stage).

Dinosaur Trackway

Pictures show a set of four footprints, the prints have three prominent toes and the animal was walking from right to left as you look at the photographs.  Such prints are known as trace fossils.  Trace fossils preserve evidence of the activity of organisms, such as their tracks, trails, burrows or borings.  As these type of fossils are not subject to be moved by natural forces, as in the case of dinosaur bones for example, where an animal’s carcase can be moved a long way from where it died to where the body finally comes to rest and is fossilised, trace fossils are direct in situ evidence of the environment at the time and place the fossils were formed.

Unfortunately, as with most photographs of this type, there is nothing in the picture to give scale.  However, it does look like these particular prints were made by herbivorous ornithopod dinosaurs, perhaps something from the Iguanodontidae or a member of the Hypsilophodontidae.

These types of animals were relatively common during this part of the Cretaceous.  Iguanodontids have been associated with Australia, Asia, Europe, the UK and Africa.  Iguanodon for example, was one of the first dinosaurs to be scientifically described, although the taxon is currently under review.

Typical Ornithopods

Iguanodontids are typical ornithopods, with beaks, narrow mouths and banks of grinding teeth.  Most of these dinosaurs were heavily built quadrupeds, but also capable of walking on their hind legs.  The digits of the hands of the forelimbs were specialised and modified.  The thumb for example (digit one), was a large spike, probably used for defence.  The long, deep tail helped balance the animal as it walked.

An Illustration of Iguanodon

Picture credit: Everything Dinosaur

To see a model of Iguanodon and other ornithopod dinosaurs: Dinosaur and Prehistoric Animal Models.

Studying Dinosaur Tracks

By studying trackways, scientists can gain an appreciation of animal behaviour.  For example, if several tracks of a single species are preserved, all heading in the same direction this may indicate herding behaviour.  The velocity of the animal that made the tracks can be calculated using a formula and measuring the stride length and other items related to the leg speed of the animal.

The fossil site is located in the Ancash region of central Peru, approximately 250 miles north-east of Lima.  At a height of over 4,600 metres above sea level, this fossil dig site is believed to be one of the highest prehistoric fossil sites found to date.

Insight into the Isle of Wight during the Cretaceous

The Wealden Group of the Wessex Basin is exposed on the surface in the coastal cliffs of the Isle of Wight off the English south coast.  This strata is famous for its abundance of well preserved dinosaur fossils, both body fossils and trace fossils.

Dinosaurs and other prehistoric animals from the Mesozoic have long been associated with this island, but now a new study into the island’s ancient fauna and flora has helped provide fresh insight into the diversity of life during the reign of the dinosaurs.

Forty-Eight New Species

For Dr Steve Sweetman of the University of Portsmouth, the research has led to the identification of 48 new species of prehistoric animal including Deinonychus sized dromaeosaurs and large pterosaurs.  The work of Dr Sweetman and his colleagues has enabled scientists to fill in a number of gaps in the Early Cretaceous eco-system and provide much more detail than previously available on the smaller animals that shared the dinosaur’s habitat.

The Isle of Wight’s dinosaurs are globally significant; a large number of different dinosaur species have been discovered in the rocks that make up the island.  Most of the fossils date from approximately 135 – 130 million years ago (Hauterivian to Barremian Formation).  The island, during this part of the early Cretaceous was an extensive flood plain that linked the continents of Africa, Europe and what was to become the Americas.  The area formed a land bridge and as well as being a rich and fertile environment in itself it may have been on the migration route of many types of prehistoric animal.

Cretaceous Ecosystem

The number of new species discovered by Dr Sweetman and his team is remarkable, especially when all the work to prepare and identify the fossils, many of which are minute, has been undertaken in just 4 years.

Dr Sweetman’s haul includes eight dinosaurs, six mammals and fifteen different types of lizard all taken from cliffs of the Isle of Wight.  Thanks to his efforts we now have a better understanding of the eco-system and have the opportunity to study in more detail some of the smaller faunal types.

However, Dr Sweetman did find fossil evidence of brachiosaurs, the largest dinosaurs known from UK strata.

Rather than wait for fossils to be weathered out of the cliffs, he excavated a block of sediment approximately 3,500 kilogrammes in weight and then removed it all to a preparation area, where it was dried and then each individual grain was scrutinised.  As well as larger items such as fossil bone, he discovered tiny teeth, fossilised jaws and other micro-fossils that enabled him to build up a picture of life during the Early Cretaceous.

An Illustration of the Isle of Wight Cretaceous Fauna

Picture credit: Mark Witton

Systematic Working

Dr Sweetman explained that his technique was more comprehensive than traditional palaeontological methods and his systematic working has enabled such a rich picture of life to be built up.

“It has taken me just four years of hard graft to make my discoveries.  In the very first sample I found a tiny jaw of an extinct newt-sized, salamander-like amphibian and then new species just kept coming” he commented.

Dr Sweetman went on to add:

“Although we knew a lot about the larger species that existed on the island during the Early Cretaceous, no-one had ever filled in the gaps.  With these discoveries I can paint a really detailed picture of the creatures that scurried at the feet and in the shadows of the dinosaurs”.

This new study will cement further the reputation of the University of Portsmouth as well as reinforcing the belief that the Isle of Wight remains one of the most important sites in the world for Lower Cretaceous fossils.

For models and replicas of Early Cretaceous prehistoric animals: CollectA Prehistoric Life Models and Figures.