Ieldraan melkshamensis – The Monster of Melksham

A new species of prehistoric marine crocodile has been described after an amazing effort by the preparators at the Natural History Museum (London), to separate this crocodile’s partial skull and fragmentary jaw bones from an extremely hard concretion, in which the fossils were entombed.  Although in very poor condition, the research team from the University of Edinburgh as well as the Natural History Museum, were able to identify enough unique anatomical traits (autapomorphies), to allow a new species to be erected.

The new marine crocodile (metriorhynchid) has been named Ieldraan melkshamensis, the species name honouring the town of Melksham in Wiltshire where the fossil material was unearthed.

Ieldraan melkshamensis – One Tough Crocodylomorph with a Very Tough Skull

Ieldraan melkshamensis fossil.

Picture credit: University of Edinburgh/Davide Foffa

Prehistoric Marine Crocodile

The specimen was acquired by the Natural History Museum in 1875, but because of its poor condition it did not attract a lot of scientific attention.  The fossil being entombed within an extremely hard concretion (septarian concretion), meant any form of scientific study was extremely limited.

Mark Graham, Senior Fossil Preparator at the Natural History Museum explained the problem:

“The specimen was completely enclosed in a super-hard rock nodule with veins of calcite running through, which had formed around it during the process of fossilisation.  The work took many hours over a period of weeks, and great care had to be taken to avoid damaging the skull and teeth as they became exposed.”

Ieldraan melkshamensis – Newest member of the Metriorhynchidae

Measuring more than three metres in length, Ieldraan melkshamensis was one of the most powerful and dangerous marine predators in the warm, shallow seas of western Europe some 163 million years ago (Callovian faunal stage of the late Middle Jurassic).  The teeth with their distinctive striations (series of ridges running down the length of the teeth) indicate that this large crocodylomorph, which was very distantly related to today’s crocodilians, fed on large prey items.  It might have hunted other marine reptiles as well as preying on squid and fish.

It has been classified as member of the Metriorhynchidae family, specifically assigned to the sub-family Geosaurinae and a phylogenetic analysis places Ieldraan as the sister taxon of Geosaurus, perhaps the best-known of all the metriorhynchids, having been named and described over 100 years ago.

A Model of a Typical Metriorhynchid Crocodylomorph (Plesiosuchus)

Prehistoric marine crocodile – Plesiosuchus.

The Plesiosuchus model shown above is part of the Wild Safari Prehistoric World model collection, replicas of marine crocodiles are quite rare, to learn more about this model series and to view the range at Everything Dinosaur: Safari Ltd: Wild Safari Prehistoric World”.

A Sister Taxon to Geosaurus

The authors of the scientific paper, published in the “Journal of Systematic Palaeontology” conclude that if this new species is a sister taxon to Geosaurus, this places it in the Geosaurini clade and this data suggests that the major Geosaurini lineages originated millions of years earlier than previously thought.

Lead author Davide Foffa (School of GeoSciences at the University of Edinburgh), stated:

“It’s not the prettiest fossil in the world, but the Melksham Monster tells us a very important story about the evolution of these ancient crocodiles and how they became the apex predators in their ecosystem.  Without the amazing preparation work done by our collaborators at the Natural History Museum, it would not have been possible to work out the anatomy of this challenging specimen.”

Prehistoric Marine Crocodile on Patrol – Plesiosuchus manselii

Plesiosuchus manselii illustrated.

Picture credit: Fabio Manucci/University of Edinburgh

Visit the Everything Dinosaur website: Everything Dinosaur.

Fossils of Biggest Dinosaur Found to Date in Thailand Reported

Everything Dinosaur has received reports that news sources are stating that fossils of a very big dinosaur, a sauropod, have been found in Thailand.  The first dinosaur bone from Thailand was discovered back in 1976, since then, as the country’s geology has been mapped and explored, a number of exciting dinosaur fossil discoveries have been made, mostly by employees of the Department for Mineral Resources, which is part of the Ministry for Natural Resources and the Environment.

Thailand’s Biggest Dinosaur Discovery

Thailand has quite extensive Mesozoic-aged exposures from both marine and non-marine environments.  To date, team members think that the largest dinosaur known from Thailand would be Phuwiangosaurus (P. sirindhornae), which is estimated to have reached a length of about twenty metres and weighed as much as seventeen tonnes.

The First Every Dinosaur Fossil from Thailand

The distal end of a sauropod femur.

Picture credit: Department of Mineral Resources (Thailand)

The photograph above shows the first dinosaur fossil to have come to the attention of science found in Thailand.  The distal end (the part furthest away from the body) of a femur was found eroding out of a stream bed in 1976.  Since then, a number of dinosaur genera have been named and described including an iguanodont (Sirindhorna khoratensis) and two sizeable theropods (Siamotyrannus isanensis and Siamosaurus suteethorni).

A senior government official (Niwat Maneekut, deputy director-general of the Department of Mineral Resources), is reported to have said that the fossils come from the north-east of the country.  A single fossilised bone was found by a villager in the Nong Bua Raheo district of  Chaiyaphum province, around two hundred miles north-east of the capital Bangkok, last year, but more recent excavations led by palaeontologists from the Department of Mineral Resources had recovered a further twenty pieces of bone.

Information remains patchy, but the fossils are estimated to be around 100 million years old and scientists are conducting more research.

Phuwiangosaurus is Believed to be a Member of the Euhelopodidae and Therefore Similar to Euhelopus

Euhelopus scale drawing. Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

For models of sauropods and other dinosaurs: Dinosaur and Prehistoric Animal Models.

Baby Ichthyosaurus communis Dined on Squid

A team of UK-based scientists have identified the youngest and therefore the smallest specimen of Ichthyosaurus communis known to science and, just for good measure, they have found what could have been the marine reptile’s last meal.  Inside the body cavity of the seventy-centimetre-long fossil, the researchers found tiny “hook-like” structures, these are the less digestible parts of squid and therefore, the scientists were able to deduce that this young Ichthyosaurus had recently fed on cephalopods.

A Young Ichthyosaurus communis Attacking a Prehistoric Squid

A neonate Ichthyosaurus attacks a squid.

Picture credit: Julian Kiely

The artist Julien Kiely has kindly reconstructed the new-born in this fantastic scene, which depicts the moment a newly born Ichthyosaurus communis attacks a squid.

Commenting on the significance of this discovery, one of the authors of the scientific paper, published today in the journal “Historical Biology – The International Journal of Paleobiology”, Dean Lomax stated:

“It is amazing to think we know what a creature that is nearly 200 million years old ate for its last meal.  We found many tiny hook-like structures preserved between the ribs.  These are from the arms of prehistoric squid.  So, we know this animal’s last meal before it died was squid.”

From the Biggest to the Smallest

University of Manchester palaeontologist Dean Lomax, in collaboration with German colleagues, had recently published a paper describing the largest specimen of Ichthyosaurus communis, a female that turned out to be pregnant when she died.  Everything Dinosaur wrote an article about the research in August*, as well as having described the biggest I. communis, just a few weeks later, this new paper, describes the smallest.

Palaeontologist Dean Lomax Holds the Neonate Ichthyosaurus communis Specimen

Palaeontologist Dean Lomax holding the baby Ichthyosaurus fossil.

Picture credit: University of Manchester/University of Birmingham

*To read the article about the largest Ichthyosaurus communis specimen: Palaeontologists and the Pregnant Ichthyosaurus.

Ichthyosaurus communis

Several species of Ichthyosaurus have been identified, but Ichthyosaurus communis was the first, being named and described in 1822 from fossil material discovered by Mary Anning.  These reptiles were viviparous and a number of specimens showing embryos preserved inside their mothers are known.  However, this Ichthyosaurus is one of only a handful of fossils that represent very young animals.  As it was not preserved in association with a larger specimen (the mother) and as there are stomach contents present, it is likely that this fossil represents an independent, recently born animal, the first neonate Ichthyosaurus communis skeleton to be described.

The Ichthyosaurus Fossil on Display at the Lapworth Museum of Geology, University of Birmingham

The neonate I. communis specimen.

Picture credit: University of Manchester/University of Birmingham

The fossil is definitely a new born and not a dwarf species of ichthyosaur as the scientists noted the large ring of sclerotic bone relative to the eye socket and the poorly ossified (highly cancellous) bones of the skull and other parts of the skeleton, these signs all indicate that these are the fossilised remains of a very young marine reptile.

Niche Partitioning in the Ichthyosauria

The new specimen is from the collections of the Lapworth Museum of Geology, (University of Birmingham).  Palaeontologist Nigel Larkin, a research associate at Cambridge University, cleaned and studied the specimen in 2016,  as he prepared the fossil, he became aware of its potential significance.  Nigel has recently been involved in an extensive restoration project at Biddulph Grange in Staffordshire.  He has been helping to restore the Victorian Geological Gallery at this National Trust property to its former glory.

As one of the most highly respected fossil preparators in the UK, Nigel was able to reveal the fossil’s secrets as he cleaned and helped to preserve the delicate marine reptile skeleton.

To read an article about the Geological Gallery preservation project at Biddulph Grange: Fossil Hunting at Biddulph Grange.

The discovery of squid remnants in the gut area suggests these types of ichthyosaur specialised in hunting cephalopods.  Commenting on the implications of this fossil, Dean Lomax explained:

“This is interesting because a study by other researchers on a different type of ichthyosaur, called Stenopterygius, which is from a geologically younger age, found that the small – and therefore young – examples of that species fed exclusively on fish.  This shows a difference in prey-preference in new-born ichthyosaurs.” 

Visit the website of Dr Dean Lomax: British Palaeontologist Dr Dean Lomax.

This could hint at niche partitioning, whereby similar species use different resources within an environment to reduce direct competition and to help them co-exist.

Dean Lomax and Nigel Larkin in Front of the Jurassic Seas Exhibit (Lapworth Museum of Geology)

Dean Lomax (left) and Nigel Larkin (right) in front of the Lapworth Geological Museum exhibit.

Picture credit: University of Manchester/University of Birmingham

How Old is the Fossil?

The specimen, part of the vertebrate fossil collection of the Lapworth Museum of Geology, (University of Birmingham), has no provenance data associated with it.  Unfortunately, there were no collection notes or other details to help the palaeontologists to identify where the fossil came from.  However, permission was granted for Nigel to remove a small portion of the matrix surrounding the fossil.  He passed this on to Ian Boomer (University of Birmingham) and Philip Copestake (Merlin Energy, Resources Ltd), so that they could analyse the rock for microscopic fossils.

Based on the types of microfossil preserved, the scientists were able to identify that this ichthyosaur was around 199-196 million years old, (uppermost Hettangian faunal stage to lowermost Sinemurian of the Early Jurassic).

Nigel outlined the difficulties the team faced:

“Many historic Ichthyosaur specimens in museums lack any geographic or geological details and are therefore undated.  This process of looking for microfossils in their host rock might be the key to unlocking the mystery of many specimens.  Thus, this will provide researchers with lots of new information that otherwise is lost.  Of course, this requires some extensive research, but it is worth the effort.”

In addition, establishing a microfossil signature for a fossil may also help in those cases where theft of fossil material is suspected.

Ichthyosaurus communis is Scanned in High Resolution

As part of the study, the skeleton was Micro CT-scanned and a three-dimensional digital model was created by Steve Dey of ThinkSee3D Ltd.  Using medical imaging software, Steve converted the three sets of CT cross-sectional images (from scans of the tail, middle section and head) into a single digital three-dimensional model of the whole animal.  This non-destructive technique provided further key information helping to identify the species and potentially, helping to provide new data on Ichthyosaur ontogeny.

The beautiful new-born Ichthyosaurus is on display in the recently refurbished Lapworth Museum of Geology, University of Birmingham, which was nominated for the 2017 Art Fund Museum of the Year.

The scientific paper: “The First Known Neonate Ichthyosaurus communis Skeleton: A Rediscovered Specimen from the Lower Jurassic, UK” by Lomax, D. R., Larkin, N. R., Boomer, S., Dey, S. and Copestake, published in “Historical Biology”.

Visit the award-winning Everything Dinosaur website: Everything Dinosaur.

Jidapterus edentus Gets Grounded

A team of researchers, writing in the on-line, academic, open access journal PLOS One, have published a reassessment of the Early Cretaceous pterosaur Jidapterus (J. edentus).  This flying reptile, with a wingspan estimated to be between 1.6 and 1.7 metres, is one of a number of flying reptiles known from the Lower Cretaceous deposits of the Jiufotang and Yixian Formations, which between them have helped palaeontologists to build up a detailed picture about life in northern China some 125 million years ago (Jehol Biota).

In this new study, Jidapterus is identified as a valid genus (there had been some doubts raised over whether or not the single fossil specimen known represented another closely related pterosaur species – Chaoyangopterus zhangi).  In addition, the authors postulate that Jidapterus might have been a ground dwelling forager, Everything Dinosaur team members have speculated that Jidapterus only took to the trees to evade predators or perhaps to roost.

The Only Known Specimen of Jidapterus edentus with an Accompanying Line Drawing

The holotype fossil of Jidapterus edentus and accompanying line drawing.

Picture credit: PLOS One

 Jidapterus – A Tricky Pterosaur

Named in 2003, Jidapterus is known from a single, partially articulated and nearly complete specimen (holotype RCPS-030366CY).  It is a member of an enigmatic family of pterosaurs called the Chaoyangopteridae (pronounced Chow-yang-op-tery-rid-aye).

Several species have been named, from Brazil (Lacusovagus) and from Lebanon (Microtuban), to read more about the Lebanese pterosaur, the first flying reptile to be described from this part of the world: Pterosaur Fossil Flies Home.  Most of what palaeontologists know, about this family of flying reptiles, distantly related to the giant azhdarchid pterosaurs, comes from studying the fossilised remains of chaoyangopterids from northern China.  Trouble is, these delicate flying reptile specimens associated with Liaoning Province are squashed as flat as a pancake.  The researchers identified a number of anatomical traits (autapomorphies) that reinforce the idea that Jidapterus should be considered as a distinct genus.

In addition, the scientists examined the feet and claws of Jidapterus and concluded that this flying reptile, once thought to have been a piscivore, was probably omnivorous, foraging on the forest floor for seeds and other plant material, as well as snatching up invertebrates and small creatures.  Whether or not the narrow, pointed beak (labelled in the diagram above) was entirely toothless remains open to debate.

The scientific paper: “The Toothless Pterosaur Jidapterus edentus (Pterodactyloidea: Azhdarchoidea) from the Early Cretaceous Jehol Biota and its Paleoecological Implications” by Wen-Hao Wu, Chang-Fu Zhou and Brian Andres published in PLOS One.

Visit the Everything Dinosaur models section for replicas of pterosaurs: Dinosaur, Marine Reptile and Pterosaur Models.