New Dinosaur Species Discovered – The Origins of a Native Indian Legend Perhaps?

Researchers reporting in the on line scientific journal PLoS One have described the discovery of a new species of primitive, long-necked dinosaur that was buried in a collapsed sand dune approximately 185 million years ago.  The fossil was discovered eroding slowly out of sandstone strata, close to the archaeological remains of an ancient native Indian settlement.  Could these bones be the source of the Navajo Indian legend of a sand monster that buried its victims alive in the dunes?

The sandstone block has been partially removed from its burlap and plaster covering.  The bones making up the right hand can clearly be seen, the five digits with sharp claws on the end of the fingers.  The fossil is articulated and nearly complete with just the skull, some elements of the toes and a shinbone missing.  Unfortunately, skull material is often absent with fossils of this nature.  The relatively small skull, balanced on a long neck is very often not present when the rest of the fossilised skeleton is discovered.

Seitaad ruessi

The dinosaur has been named Seitaad ruessi.  This dinosaur has been named to honour the ancient American Indian sand monster which was known as “Seit’aad”, the species name is in memory of the poet and naturalist Everett Ruess who disappeared in the sandy desert of southern Utah in 1934.

This dinosaur is a member of the Sauropodomorpha, long-necked herbivores with lizard-like feet.  It would have been around 3-5 metres long and perhaps over 1 metre high at the hips.  It lived during the early Jurassic (Toarcian faunal stage), approximately 185 million years ago.  Southern Utah during the early Jurassic was a dry, arid desert environment but with isolated strips of lush and verdant vegetation close to water sources.

Dinosaur

This dinosaur was probably a facultative biped, normally walking on all fours but capable of running or standing just on its hind legs as and when necessary.

The analysis of the fossilised bones was undertaken by palaeontologists Joseph Sertich, a Stony Brook University doctoral student and Mark Loewen of the Utah Museum of Natural History.

Commenting on the discovery, Sertich said in a statement:

“Although Seitaad was preserved in a sand dune, this ancient desert mush have included wetter areas with enough plants to support these smaller dinosaurs and other animals.”

Although, Sertich went onto add:

“Just like in deserts today, life would have been difficult in Utah’s ancient sand sea.'”

The fossil was discovered in 2004 and removed from the sandstone cliff the following year.  It is likely that more work will be carried out on the matrix that contains the fossil so that more of the skeleton can be revealed.

This particular discovery helps to confirm the success of the Sauropodomorpha in the Early Jurassic, this type of dinosaur was relatively common and would have made up some of the larger elements of the mega fauna on the super-continent of Pangaea.

The research team have stated that they believe that this particular dinosaur was unfortunate to have been buried suddenly in a collapsing sand dune, perhaps the sand was disturbed as a herd of these animals moved across the landscape.  This dinosaur was engulfed and the remains ended up stood on their head.

Plateosaurus

Perhaps the best known Sauropodomorpha is Plateosaurus (prosauropod), one of the best known dinosaurs of all.  Many thousands of plateosaur fossils have been found in Europe.  It was clearly one of the most common types of dinosaur in the Late Triassic.

An Illustration of Plateosaurus

Picture credit: Everything Dinosaur

To view models of Plateosaurus and other Sauropodomorpha members: CollectA Prehistoric Life Models.

Roy Chapman Andrews 1884-1960

Today, March 11th, marks the fiftieth anniversary of the death of Roy Chapman Andrews one of the most colourful and fascinating naturalists and museum scientists of the 20th century.  He led a number of pioneering expeditions to the Gobi desert of central Asia in the early 1920s and although the original objective of these scientific expeditions was to find mammal fossils, he is best remembered for the dinosaurs he helped discover.

Roy Chapman Andrews

Working for the American Museum of Natural History (New York), Roy Chapman Andrews and his colleagues on these expeditions discovered the first-known fossilised dinosaur nests and hatchlings as well as many new dinosaurs including Protoceratops, Velociraptor and Oviraptor.

To see models of Velociraptor, Protoceratops and Oviraptor: CollectA Age of Dinosaurs Popular Models.

An Oviraptorid Dinosaur Sitting on a Nest

An Oviraptor and its nest. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

Many people believe that the real life adventures of Roy Chapman Andrews formed the basis for the fictional character Indiana Jones.

To read an article about this: Would the real Indiana Jones Please Step Forward.

Although regarded as a maverick by some academics, the contribution of Roy Chapman Andrews to the collection of the American Museum of Natural History is widely recognised.  Indeed, many of the methods and techniques pioneered by his team in the 1920s in their expeditions to remote parts of the world are still used by scientific expeditions today.

Ancient Indian Constrictor Attacked Baby Sauropods

Scientists have discovered the remarkable fossil of a baby dinosaur that was attacked by a snake.

An adult sauropod would have had few enemies, their sheer size and strength making them invulnerable to attack from all but the most determined or foolhardy theropod.  However, the discovery of a fossil from Gujarat in Western India indicates that for baby long-necked dinosaurs, life was very hazardous, even at the moment of hatching from their eggs.

In a paper published in the scientific journal “PLoS Biology”, a team of scientists report on the macabre discovery of a 3.5 metre long snake caught in the act of raiding a sauropod dinosaur’s nest and attacking a newly hatched dinosaur.  A number of sauropod nesting sites have been discovered in Western India, in Late Cretaceous deposits (Maastrichtian faunal stage).  The nest was that of a titanosaur, the last group of sauropods to evolve.  Palaeontologists are confident that these large herbivores migrated to traditional nesting sites year after year and laid their eggs in extensive nesting colonies.

The females would scrape out a hollow in the ground and then carefully lay a clutch of eggs (as many as twelve per nest), then they carefully covered the eggs again, perhaps putting a layer of vegetation on top of the eggs to help incubate them.  Then the nest was abandoned and the eggs and any hatchlings left to their fate.  Such nesting sites would have provided a number of small predators, dinosaurs, lizards, birds and of course snakes with an easy meal once the adults had moved on.

Baby Dinosaurs

Primitive constrictor snakes had been found in association with dinosaur nesting sites on previous occasions, but this remarkable fossil shows a snake caught in the act of attacking a 40 cm long hatchling.  The fossil, known as an “ethofossil” as it shows feeding behaviour; comes from a sauropod nesting site first discovered in 1984.  The remains of the snake are preserved in close association with unhatched eggs, egg fragments and some of the bones of the newly emerged sauropod.  The nesting site is adjacent to an ancient river bed.  The snake and its victim were suddenly buried by sediment, perhaps as the result of a downpour or the collapse of part of the river bank.

The discovery was made by Jeffrey Wilson, a Professor at the University of Michigan (United States).  He had heard about the amazing fields of dinosaur eggs discovered in India and when shown a small block of matrix with the fossilised egg entombed within it, he observed the remains of the snake vertebrae which were just visible on the surface of the rock.

Professor Wilson commented:

“I was stunned when I saw it, because sort of leaping out at me were the peculiar articulations between the vertebrae of a snake”.

Having been granted permission by the Indian Government, Professor Wilson returned home with the fossil and began the year long process of cleaning and preparing the fossil.

Grain by grain the surrounding sandstone rock matrix was removed and the eggs, the snake and the hatchling were slowly and surely revealed.  The grim scene became apparent, a moment frozen in time when a 3.5-metre-long predator attacked the defenceless hatchling.

Recalling the moment when the details of the fossil were revealed, Professor Wilson stated:

“It was amazing.  We realised that not only did we have an egg, not only did we have a chain of vertebrae, but they were arranged in a coil, and on top of the coil was a skull.”

Coiled Around the Broken Eggshell

The snake was coiled around the broken eggshell and adjacent to the coil, eggshell and the bones of a baby titanosaur.  The primitive snake was unable to open its jaws wide enough to swallow the large dinosaur egg, but with an estimated gape in excess of 16 cm wide, it could manage to constrict and then swallow the newly emerged dinosaur hatchling.  It must have detected the nest and then moved in to attack the youngster as it emerged from its egg.

Wilson says scientists have since found three snake fossils and more eggs at the same site this one came from.  They add new details to a 67-million-year-old story, says the University of Michigan scientist.

Snakes and other predators would remember the location of a titanosaur nesting site and perhaps an entire eco-system sprang up around the annual dinosaur nesting.

The Fossil of the Cretaceous Snake and Sauropod Remains

Snake attacks baby dinosaurs.

Picture credit: Wilson et al 2010

The snake, a new genus has been named and described by the U.S. based team, it has been called Sanajeh indicus which means “ancient gaped one from India”.  Two other snake fossils have been found in this area, indicating that perhaps snakes and other predators congregated around the nesting site looking for an easy meal.

Palaeontologist Jason Head, of the University of Toronto, who helped produce the research paper used two recent movie titles to describe his feelings about the fossil discovery:

“It’s Anaconda meets Jurassic Park” he stated.

Dr Head went onto comment:

“These sauropods would lay these huge fields of eggs that we find in India, just kind of kilometres of dinosaur eggshell, and so with these hatchling dinosaurs it must have just been a smorgasbord where a whole ecosystem of predators could basically come in and feed on them.”

An Illustration of the Dinosaur/Snake Fossil

Attacked by a snake.

Illustration credit: Wilson et al 2010

The diagram above shows a detailed illustration of the fossil, looking down onto it.  The remains of the baby sauropod are to the right with the head of S. indicus in the top left corner.

Sanajeh indicus had a different jaw arrangement compared to modern constrictors such as Boas.  It could not unhinge its jaws to swallow large prey like a modern snake, instead the lizard like jaw was able to gape which permitted it to swallow prey wider than itself.

Dr Head went onto state:

“This is the first direct evidence of feeding behaviour in a fossil of a primitive snake, and shows us that the ecology and early evolutionary history of snakes were much more complex than we would think just by looking at modern snakes today.”

The evolution of large-gape snakes such as pythons and boas ( known as Macrostomatans) capable of feeding on large prey and their ancestral habitat has remained controversial.  Modern-day pythons have excellent jaw adaptations and an elongated skull; fully grown pythons have a gape as wide as nearly 60 cm; enabling them to swallow animals much larger than themselves. Among other adaptations, Macrostomatans have really long lower jaws and increased mobility of jaws compared with the more primitive S. indicus.

The lower jaw of S. indicus is approximately 12 cm long, and this, in conjunction with other anatomical features that give the jaws greater mobility and flexibility would have enabled Sanajeh indicus to swallow hatchling dinosaurs.

Dr Head commented that the snake probably made up for its inability to unhinge its jaws completely like a modern constrictor by growing large to increase its ability to gape.  It would have grown rapidly by consuming as many young dinosaurs as it could during the breeding season and then perhaps lying dormant until the following year.  For the sauropods, as they emerged from the nests they were extremely vulnerable without their parents to protect them.  It would seem that the best survival strategy for a young titanosaur would be to grow up as fast as possible.

Everything Dinosaur stocks a range of titanosaur models and even replicas of giant prehistoric snakes (Titanoboa). Visit the model section of the company’s website: Prehistoric Animal Models and Replicas.

The scientific paper: “Predation upon Hatchling Dinosaurs by a New Snake from the Late Cretaceous of India” by Jeffrey A. Wilson, Dhananjay M. Mohabey, Shanan E. Peters, Jason J. Head published in PLoS Biology.

Was Spinosaurus a Swimmer?  Watery Habitat for Largest Theropod

Scientists have found evidence of flying dinosaurs, there is evidence to suggest that some dinosaurs were at home in the trees, some lived in burrows, but a dinosaur that lived an aquatic existence?  That surely must be a step too far for a group of reptiles whose suitability for life on land and simple hinge-like ankle joints gave them a significant advantage over other land animals in the post Permian extinction race for dominance of the Earth.

Swimming Spinosaurs

However, a team of French scientists have concluded that at least one type of dinosaur – the spinosaurids may have spent a considerable amount of time in water, in fact about as much time in the water as extant species of crocodiles do today.

Romain Amoit from the University of Lyon (France) and his colleagues studied the amount of an isotope of oxygen within the fossilised teeth of a number of dinosaurs.  They then compared their findings to known aquatic animals from the fossil record, turtles and crocodiles and from these results they have concluded that the spinosaurs probably spent most of their time in a watery environment.

The spinosaurids, most famously Spinosaurus, the dinosaur villain in the movie Jurassic Park III were a widespread Cretaceous theropod dinosaur.  Remains of such creatures have been discovered in England (Baryonyx), Africa, South America, China, Thailand and Japan.  These dinosaurs were characterised by having long, narrow jaws armed with many sharp, straight teeth, in most cases resembling the teeth of crocodiles.  Most of this group of large, carnivores had humps or elaborate sails along their backs.

Spinosaurus aegyptiacus, was named and described by the great German palaeontologist/geologist Ernst Stromer von Reichenbach in 1915.  He had led a number of fossil hunting expeditions to North Africa between 1911 and the outbreak of World War I.  Unfortunately, very little spinosaur fossil material or information is left from these expeditions as the Munich museum in which these items were stored was utterly destroyed by an American bombing raid during World War II.

However, based on the notes and illustrations from Stromer’s time plus more recent Spinosaurus remains from Morocco, some scientists have claimed that this type of spinosaur is the largest known predatory dinosaur in the fossil record with some size estimates putting Spinosaurus at more than 17 metres long, much larger than the biggest Tyrannosaurus rex, or Giganotosaurus.

An Illustration of a Spinosaurus

The “classic” Papo Spinosaurus dinosaur model.

Picture credit: Everything Dinosaur/Papo

The picture shows a typical model of a Spinosaurus (2010), the distinctive big claw on the thumb can clearly be seen.  Evidence of these types of creatures being fish eaters has been found before, for example, the remains of fish scales (Lepidotes) found in association with the Surrey Baryonyx skeleton, but the French team go further, they claim that as well as eating fish, these animals spent much of their time in the water.

To view the Papo Spinosaurus model and other replica figures in the Papo “Les Dinosaures” range: Papo Dinosaur and Prehistoric Animal Models.

In a report published in the scientific journal “Nature News”, the French team provide evidence that spinosaurs avoided competition with the other large, carnivorous dinosaurs that shared their environment, by specialising as fish-eaters and by being very much at home in their watery habitats.  Such areas would have been avoided by the other types of predatory dinosaurs, the allosauroids for example, after all, there is plenty of evidence to suggest such large and heavy creatures were prone to becoming stuck in soft mud and sand in pursuit of a herbivore that had become mired.

Unable to extricate themselves from what would turn out to be their muddy grave (predator traps) many fossils of allosaurs have been found under these circumstances.

Amiot and his team took a look at oxygen isotopes locked away inside the preserved enamel of the spinosaur’s teeth and compared them to the oxygen isotopes found in the teeth of crocodiles and other dinosaurs, and turtle-shell fragments from the same geological period – the Cretaceous.

It is known that animals that spend a lot of time in a dry environment lose water through breathing and through evaporation from skin.  As one type of oxygen isotope; oxygen-16 is lighter than another isotope – oxygen-18, it is more readily released with water vapour. As a result, oxygen-18 becomes more concentrated in tissues and when tooth enamel is formed.  Analysing the types of oxygen isotopes preserved in the fossil fragments could provide an indication as to how close to water, or at least how close to a humid, watery environment did extinct animals live.

The researchers reasoned that if spinosaurs were aquatic, then the concentration of oxygen-18 in their tissues would closely match aquatic animals such as crocodiles and turtles and be lower than the isotope values of other dinosaurs, as the other dinosaurs would be presumed to be more terrestrial in their habits.  Sort of “land lubbers” to the spinosaurs being “jolly jack tars”.

The University of Lyon team studied the oxygen isotopes of a total of 133 Cretaceous specimens, a mixture of spinosaurs, other dinosaurs and animals known for their nektonic behaviour (active swimmers), such as crocodiles and turtles.  Their study showed that the spinosaurs had oxygen-18 levels that were significantly lower than those found in other more terrestrial dinosaurs.  Interestingly, the oxygen-18 values in crocodiles and spinosaurs were not significantly different.  The French team have postulated that this is evidence that spinosaurs were dwelling in aquatic habitats, perhaps occupying a specific niche in the Cretaceous food chain.

Spinosaurs in Aquatic Habitats

The evidence from the French scientists does suggest that these particular theropods may have spent a considerable amount of time in the water.  The large thumb-claw, a characteristic of the Spinosauridae would have made an effective fish hook, spearing fish as the Spinosaurus stood on the bank fishing, like a modern Grizzly Bear, but equally, it could have been used to help steady this large animal and retain its grip on the muddy bottom of a riverbed.

We think this debate is going to run and run, for example, although fish scales are associated with the Baryonyx fossils found in a Surrey clay pit, so are the remains of a small iguanodontid.  Other spinosaur fossils have been associated with the fossilised remains of their last meal, a flying reptile.  Just like most crocodiles, these animals may have been unfussy eaters, devouring anything and everything that they came across.  The bones of these creatures do not show many adaptations for an aquatic lifestyle.  For instance, there is little evidence for a deepened tail to help with swimming.

Elements such as any webbing between the toes would not necessarilly have been preserved, so the jury is still out as to just how much time this dinosaur spent swimming.

It is known that dinosaurs could swim and many took to the water, traces of their tracks as they crossed lakes and rivers have been found in various parts of the world.  In one remarkable example from northern Spain, the fossilised trackway of a theropod dinosaur as it swam across a body of water has been preserved.

To read more about this remarkable trace fossil: Swimming Dinosaurs, Evidence from Spain.

The sandstone, in which the occasional claw impressions and prints have been preserved as this animal swam across the water, occasionally touching the bottom and pushing itself off again, is approximately 125 million years old.  This date coincides to the time when the spinosaurs were around, could this be evidence of a swimming spinosaur?

Dinosaur Extinction Event led to Evolution of Flightless Birds

An abundance of food in conjunction with relatively few, large ground-dwelling predators led some types of bird to give up flying and take to a wholly terrestrial, flightless existence according to a team of Australian researchers.

In a new study into the origins of flightless birds such as Emus, Rheas, Moas and Ostriches led by Dr Matthew Phillips, an ARC Postdoctoral Fellow at the Australian National University Research School of Biology, it seems that these birds became flightless independently and did not share a flightless common ancestor.  Surprisingly, the researchers, after examining the mitochondrial genome sequences of the now-extinct giant Moa birds of New Zealand; have suggested that these colossal  creatures are most closely related to small flying birds native to South America.

The team used assessments of the mitochondrial DNA of extant and extinct flightless birds, their study concluded that the ancestors of the African Ostrich, Australasian Emu plus the Cassowary, South American Rheas and New Zealand Moa became flightless independently, in close association with the extinction of the dinosaurs about 66 million years ago.

Commenting on the results from this new study, Dr Phillips stated:

“Many of the world’s largest flightless birds, known as Ratites, were thought to have shared a common flightless ancestor.  We followed up on recent uncertainty surrounding this assumption.”

He went onto add:

“Our study suggests that the flighted ancestors of Ratites appear to have been ground-feeding birds that ran well.  So the extinction of the Dinosaurs likely lifted predation pressures that had previously selected for flight and its necessary constraint, small size.  Lifting of this pressure and more abundant foraging opportunities would then have selected for larger size and consequent loss of flight.”

The demise of the dinosaurs, particularly the theropod predators, ironically those dinosaurs believed to be most closely related to birds, permitted the diversity of Aves, leading to the development of a number of flightless bird types.

When Sir Richard Owen, the founder of the Natural History Museum in London and the scientist credited with first coining the phrase “Dinosauria”, was photographed next to the giant bones of a Moa bird from New Zealand, he was not aware that the dinosaur’s demise may have led to existence of such creatures.

An Illustration of a Giant, Flightless Bird (Kelenken)

The Kelenken in all its glory. Picture credit: Everything Dinosaur.

The finding of independent origins of flightlessness also solves a mystery of how these flightless birds dispersed across the world over marine barriers, their ancestors simply flew across them.

Dr Phillips stated that previous research had indicated that Ratite birds were thought to be relics from the super-continent Gondwanaland, which consisted of South America, Australia, India, Africa, New Zealand and Antarctica, all elements of the Southern Hemisphere.  This new study suggests that separate Ratites evolved too recently to have had a common ancestor on Gondwanaland before the super-continent broke up. The study also reveals that today’s flightless birds may have had their origins in the Northern Hemisphere.

Dr Phillips said:

“Not only have we shown that the separate Ratite lineages evolved too recently to have been on Gondwana before its continents drifted apart, but from our analyses we infer that at least ostriches, and possibly Ratites as a whole, have their origins in the northern continents.”

The research paper is published in the scientific journal “Sytematic Biology”, certainly there is something very intimidating when up close to birds like ostriches as they tower over your head.  They have quizzical jerky movements and when they fix you with a stare it is quite frightening.  However, if you want to see evidence of how closely related birds are to dinosaurs simply take a look at their feet.  The feet are very reminiscent of the feet of a theropod dinosaur and they are very reptilian in appearance.

For models of dinosaurs and also extinct, flightless birds: CollectA Deluxe Prehistoric Life Models.