Thylacoleo carnifex Behaviour Deduced from Cave Claw Mark Study

Don’t climb a tree in a bid to avoid an attack from a Marsupial Lion (Thylacoleo carnifex).  That might have proved very good advice to the first inhabitants of Australia who set foot on the continent some 50,000 years ago.  These early explorers would have encountered a bizarre and unique fauna dominated by giant monitor lizards, flightless birds and strange mammals, the like of which existed nowhere else on Earth.

Thylacoleo carnifex

One of the more peculiar creatures, and an animal probably best given a wide berth, was the leopard sized Marsupial Lion (T. carnifex).  The name “Marsupial Lion” for an animal about the size of a male African leopard (Panthera pardus pardus), albeit slightly heavier, may sound like a bit of a misnomer, but from a palaeontological perspective this is just one of the peculiarities surrounding this enigmatic creature.

Thylacoleo carnifex – Study Suggests These Marsupials were Capable Climbers

Capable of climbing trees.

Picture credit: Peter Trusler/Australian Post

However, a new study assessing scratches and claw marks left in the main cavern of Tight Entrance Cave, located in south-western Australia, has provided fresh insights into the likely behaviour and habits of these prehistoric animals.  This new research suggests that Thylacoleo carnifex was an able climber and that it probably raised its young in caves.

A Chequered History

The habits and diet of the Marsupial Lion has puzzled scientists, almost since the initial scientific description by Richard Owen (later Sir Richard Owen), in 1859.  At first, this animal was thought to be a carnivore, but as a member of the Order Diprotodontia along with kangaroos, it was then suggested to have been herbivorous.

Anatomical analysis reveals Thylacoleo to be a robust animal with strong back legs and powerful shoulders, not particularly adept at running.  It had been thought that this animal filled the ecological niche occupied by bears outside Australia.  Recently, the idea that the Marsupial Lion was an apex predator that could drag prey up into trees became popularised.  Thylacoleo as a sort of Aussie version of a leopard was even illustrated on the front cover the prestigious magazine Prehistoric Times.

Prehistoric Times Featured Thylacoleo (Issue 85)

The front cover features a Marsupial Lion.

Picture credit: Prehistoric Times

A Tree Climber?

Scientists from Flinders University (South Australia) analysed the scratch marks left on the walls of the main chamber in the Tight Entrance Cave.  The majority of these marks were clustered on a near-vertical rock face that led up towards an exit to the surface.  That exit may be blocked today, but clearly this way out of the cave was a preferred route for many Marsupial Lions rather than using a circuitous path with a lesser gradient.

This suggests that these animals were confident and assured climbers and remarkably agile.  In addition, the study indicates that the scratches were mostly made by juveniles, this suggests that Marsupial Lions may have reared their young inside caves.

One of the authors of the research, published in the open access journal “Scientific Reports”, Associate Professor Gavin Prideaux (School of Biological Sciences, Flinders University) commented:

“Our findings indicate the Marsupial Lions were running up and down these rock piles to get out of the cave, and they weren’t using the lower-gradient, longer route.  We can be confident now and say that they could climb and if they could climb really well in the dark, underground, there’s no reason they couldn’t climb trees.”

Marks Made by Juvenile Marsupial Lions

In order to confirm that the scratches were most probably made by juvenile Marsupial Lions, co-author Samuel Arman, established a list of seven potential candidates, composed of both living and extinct species.  A model was made of a Thylacoleo paw to test how the digit and claw configuration matched against the scratch marks from the cave.  To assess the sort of claw marks made by extant animals included in the study (possums, wombats and Tasmanian devils), scratch pads were given to zoos so that they could be placed inside the enclosures where these animals were housed.  Any claw markings were examined and cross referenced against the trace fossils from the cave.

Examples of Scratch Marks from the Cave

Claw marks from the cave made (most probably) by juvenile Marsupial Lions.

Picture credit: Flinders University/Scientific Reports

The picture above shows (a) cave wall south, (b) marks from a central rock pile to the west, (c) marks from a central rock pile from the south sub-region of the main cavern, (d and e) scratches from the boulder sub-region.  Scale bar = 10 cm.

Based on this research, it seems that climbing a tree to avoid the attentions of Thylacoleo would not have been a very good idea.

The Ubiquitous Marsupial

The various eclectic theories regarding the habits of T. carnifex that have been proposed may have had something to do with the wealth of fossil material available to study.  More complete or partial skeletons of Marsupial Lions are known from cave sites than for any other extinct Pleistocene species.  Thylacoleo carnifex is amongst the best represented large carnivores known from Pleistocene fossil bearing sites.

For models and replicas of prehistoric mammals: CollectA Deluxe Prehistoric Life.

Rich Fossil Pickings from Gujarat State

Since the turn of the year, Everything Dinosaur has been receiving reports circulated by various Indian universities of further dinosaur fossil discoveries from Kutch district from the state of Gujarat (western India).  In a collaboration with German scientists from the Friedrich-Alexander University of Erlangen-Nürnberg, Bavaria (southern Germany), field team members from the Department of Geology (Kutch University, Gujarat) and Rajasthan University have uncovered the fragmentary remains of a number of dinosaurs and they have identified around 150 sites which may yield yet more fossil data.

Dinosaur Fossils

The latest discovery includes cranial material, excavated from a location close to Lodai village (Kas Hill).  Lodai village itself is located around fifteen miles north-east of the large town of Bhuj

On January 19th, field team members uncovered fragments from the hip bones of a substantial plant-eating dinosaur.  In addition, a partial leg bone was discovered.  The pieces of bone have been tentatively assigned to the Camarasaurus genus and they may represent some of the oldest dinosaur fossils ever found in India.    The fossil material has been dispatched to the Friedrich-Alexander University so that the specimens can undergo radiocarbon dating in a bid to determine an accurate age of the fossils.  Preliminary dating work suggests that the bones are at least 135 million years old (Valanginian faunal stage of the Early Cretaceous).

Sauropod Dinosaur Fossils

Estimating that these bones came from a sauropod (long-necked) dinosaur measuring around fifteen metres in length, Dr Dhirendra Pandey (University of Rajasthan), explained that such fossils provided information on the mega fauna that inhabited this part of the giant, super-continent of Gondwana.  Most of the dinosaur fossils from Gujarat State come rock strata that is actually much younger, dating from the Late Cretaceous.

A Sauropod Dinosaur Exhibit in a Museum

A sauropod (diplodocid) skeleton exhibit on display at the Frankfurt Natural History Museum (Naturmuseum Senckenberg). Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

For models and replicas of sauropods and other dinosaurs: Mojo Fun Prehistoric and Extinct Figures.

Commenting on the new discovery, Gaurav Chauhan, from the Geology Department of Kutch University stated:

“The new fossils include skull, jaw and some teeth of a dinosaur.  We still have to excavate a lot of material in order to get the fossils out.”

Hopeful to Find More Fossil Material

The team are hopeful that more fossil material may be found at this location and that the fossils may represent a new species.

A number of important dinosaur fossil finds have already been reported from this part of India.  For example, back in 2010, Everything Dinosaur reported on the remarkable discovery of a titanosaur nest site, which included the remains of a primitive snake that had died whilst attempting to raid a nest.

To read an article about this remarkable fossil find: Baby Dinosaurs Attacked by Snake.

Alabama Fossil Sheds Light on the Origins of Duck-Billed Dinosaurs

The duck-billed dinosaurs, or to be more precise, the Hadrosauroidea were a super-family of plant-eating, bird-hipped dinosaurs that dominated Late Cretaceous ecosystems throughout most of the northern latitudes.  The fossils of these large dinosaurs, some of which evolved into the biggest facultative bipeds known to science, can be seen in museums throughout the world, but little is known about the evolutionary origins of this very successful part of the Dinosauria.  However, a remarkable fossil find from Alabama (south-eastern United States), is helping to shed new light on the origins of the duck-billed dinosaurs.

The Fossils of Eotrachodon orientalis Laid Out

The skull and jaw bones including the predentary are nearest the camera.

Picture credit: Jun Ebersole, McWane Science Centre

The beautifully preserved fossils were found by amateur fossil hunters exploring a creek in Montgomery County, Alabama, when they come across one of the bones eroding out of the soft marine sediment.  Thanks to the efforts of an international team of researchers, the fossil material has been carefully prepared and it has been confirmed that these bones and the few teeth (see bottom right hand corner of the photograph), represent a new species of primitive duck-billed dinosaur.

Eotrachodon orientalis

The dinosaur has been named Eotrachodon orientalis (dawn rough tooth from the east).  It is the most complete primitive hadrosaurid dinosaur ever to be found in the eastern United States.

An Illustration and Scale Drawing of E. orientalis

The orange shaded area indicate fossils found.

Picture credit: Florida State University with additional annotation by Everything Dinosaur

In Honour of Trachodon

Lead author of the scientific paper, published this week in the “Journal of Vertebrate  Palaeontology”, Albert Prieto-Marquez, stated that the genus name honours Trachodon, a name that would be very well known to fans of dinosaurs.

Trachodon is the genus erected in 1856 by Joseph Leidy as a result of fragmentary bones and teeth having been excavated from the Upper Cretaceous rocks (Judith River Formation) of Montana.  It was one of the very first American dinosaurs described, the first duck-billed dinosaur to be named (although some of the teeth used to describe it were later identified as ceratopsian), and although the name is now regarded as a nomen dubium (not a valid genus), Trachodon appeared in countless books about dinosaurs for the best part of 120 years.  The popularity of Trachodon was helped by wonderful illustrations produced by palaeoartists such as Zdenek Burian (Trachodon and Tyrannosaurus rex).

Trachodon Became the Archetypal Duck-Billed Dinosaur

An illustration of Trachodon.

Picture credit: Everything Dinosaur

Now Trachodon has been honoured with a valid genus (Eotrachodon).  At perhaps, nine metres long, Eotrachodon orientalis was certainly not the biggest, but the fossil find is extremely significant none-the-less.  Firstly dinosaur fossil finds are rare from the south-eastern United States.  To read an article about which U.S. States have dinosaur fossils: 37th U.S. State with A Dinosaur Fossil.

Commenting on the significance of the discovery, one of the authors of the scientific paper, Gregory Erickson (Florida State University) explained:

“This is a really important animal in telling us how they came to be and how they spread all over the world.”

Did the Hadrosaurs Originate in Appalachia?

Whilst the specimen was being prepared at the McWane Science Centre (Birmingham, Alabama), the scientists were able to piece together the skull bones and identify a modified nasal area of the skull that had, until now been regarded as a characteristic associated with saurolophine hadrosaurids (solid-crested and crestless forms).  Dating the fossil to the Late Santonian faunal stage (83 million years ago), it suggests that the duck-billed dinosaurs originated on the continental landmass known as Appalachia.

During the Late Cretaceous, North America was split by into two by a wide sea (the Western Interior Seaway), Laramidia lay to the west, whilst the larger landmass of Appalachia lay to the east.  Phylogenetic analysis indicates that Eotrachodon is a basal member of the hadrosaurids and thus, it can be postulated that this group of dinosaurs evolved on Appalachia.  Land bridges formed as the Western Interior Seaway permitted these dinosaurs to migrate off this continental landmass and to spread to other parts of the Late Cretaceous world.

Reseracher Jun Ebersole, (McWane Science Centre), stated:

“For roughly 100 million years, the dinosaurs were not able to cross this barrier.  The discovery of Eotrachodon suggests that duck-billed dinosaurs originated in Appalachia and dispersed to other parts of the world at some point after the seaway lowered, opening a land corridor to western North America.”

Fossil Find Suggests Hadrosaurids Originated from Appalachia

Sweet Home Alabama!

Picture credit: Everything Dinosaur

A View of the Left Lateral Side of the Skull

Scale bar = 5cm

Picture credit: Albert Prieto-Marquez et al

Safari Ltd have produced several duck-billed dinosaur models. To view the Wild Safari Prehistoric World range of figures: Safari Ltd. Wild Safari Prehistoric World Figures.

Potential New Plesiosaur Species

A nearly complete plesiosaur skeleton that came to rest in marine sediments now located in northern Cambridgeshire might just prove to be a new species.  The fossilised remains were excavated out of a layer of rock discovered in a fenland quarry in November 2014, by archaeologists from the Oxford Clay Working Group.

The Cambridge Plesiosaur

A nearly complete plesiosaur skeleton that came to rest in marine sediments now located in northern Cambridgeshire might just prove to be a new species.  Over the next four days the team were able to excavate and remove nearly 600 bone fragments that represent a considerable portion of the entire skeleton.  Only some limb elements are missing.  The fossil, nick-named Eve, represents an individual around five and a half metres in length, early indications are that the bones show similarities with another plesiosaur known from the Peterborough area, called Picrocleidus.

Visit Everything Dinosaur’s award-winning website: Everything Dinosaur.

However, Picrocleidus is believed to have been much smaller, at less than half the length of this new discovery, and its fossils are associated with much younger Jurassic strata (Callovian faunal stage), whilst “Eve” was found in rocks dating from about 165 million years ago (Bathonian faunal stage of the Jurassic).

A Plesiosaur Specimen on Display

A long-necked plesiosaur fossil specimen.  A plesiosaur fossil specimen on display at the Oxford University Natural History Museum.

Picture credit: Everything Dinosaur

The Oxford Clay Working Group

Dr Carl Harrington, a member of the Oxford Clay Working Group, was the first person to find bones of this new sea monster.  Describing the find as “fantastic”, Dr Harrington recalled the moment he first uncovered the delicate skull bones:

It was one of those absolute “wow” moments.  I was the first human to come face-to-face with this reptile.”

The quarry is owned by building supplies company Forterra and this part of Cambridgeshire has become very well known for its Jurassic vertebrate fossil finds.  For example, the first fossils of the giant prehistoric fish Leedsichthys  (L. problematicus) were also found in the Peterborough area.  Forterra have donated the specimen to the Oxford University Museum of Natural History, where the fossilised remains are currently being prepared and studied in more detail with a view to determining whether or not this is a new species of marine reptile.

An Artist’s Interpretation of the New Marine Reptile (Plesiosaur)

Scale bar = 1 metre.

Picture credit: Nobomichi Tamura with additional annotation by Everything Dinosaur

For models and replicas of plesiosaurs and other marine reptiles: CollectA Deluxe Prehistoric Life Models.

Plesiosaurs had two pairs of  oar-like paddles which they used to propel themselves through the water, recent studies suggest that, just like extant penguins, these marine reptiles, some of whom could reach lengths in excess of fifteen metres, actually “flew” through the water.

To read more about this research into plesiosaur propulsion: Computer simulations and marine reptile underwater flight.

Nice to see that Cambridge is prepared to donate a pair of oars to Oxford, their bitter rowing rivals.