Nichollssaura borealis – Shaking its Neck from Side to Side

The long-necked plesiosaurs (Plesiosauroidea), are characterised (unsurprisingly), by their long necks, which in the case of the elasmosaurids were taken to extremes with some Late Cretaceous species having necks around seven metres in length, comprising 76 cervical vertebrae, but how did a plesiosaur use their necks?  What degree of movement did these long necks have?  These are questions that have been debated by palaeontologists for nearly two hundred years.

New research, published this week by the Royal Society, sheds light on the flexibility and neck movement in one plesiosaur, the Early Cretaceous leptocleidid Nichollssaura borealis.

The Fossilised Skeleton of a Jurassic Plesiosaur

Picture credit: Everything Dinosaur

Defining the Plesiosauria Clade

The Plesiosauria clade was very successful, originating in the Triassic and persisting until the very end of the Cretaceous.  This clade is split into three distinct groups, although palaeontologists debate the phylogeny between the Plesiosauria clade members.

1. The Plesiosauroidea – the long-necked marine reptiles, epitomised by short tails, broad bodies, four flippers, a small head and an elongated neck.
2. Pliosauridae – the short-necked plesiosaurs, with large heads, broad bodies, four flippers and much shorter necks than the Plesiosauroidea.
3. The Rhomaleosauridae – a sort of half-way house between the other two, typically possessing longer necks and smaller heads relative to the Pliosauridae, but have shorter necks and larger heads when compared to members of the Plesiosauridae.  Most known rhomaleosaurids are confined to the Early to Middle Jurassic of Europe, with most specimens assigned to this group having been found in England.

The Three Groups Within the Plesiosauria

Picture credit: Everything Dinosaur

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Studying One Member of the Plesiosauroidea – Nichollssaura borealis

The researchers from the Royal Tyrrell Museum and the University of Calgary, focused their study upon one specimen, a member of the Plesiosauroidea called Nichollssaura borealis.  This specimen was chosen as it represents a very nearly complete individual and the fossil is not distorted or crushed to any degree which might have comprised any research into neck flexibility.

There were two further, more practical reasons why N. borealis was selected.  Firstly, the specimen is housed at the Royal Tyrrell Museum and since one of the researchers involved in the study was Donald Henderson, a curator at the museum, accessing the specimen was not a problem.  In addition, with a total length of 2.6 metres Nichollssaura could squeeze into the medical CT scanner that was being used to create accurate three-dimensional images of the bones.

Once the specimen had been CT scanned, the subsequent three-dimensional models that were produced could be examined so as to conclude the range of movement afforded by the 24 bones in the neck of this plesiosaur (24 cervical vertebrae).

The Research Team Tested the Range of Neck Movement Using Three-Dimensional Models

Picture credit: Royal Society Open Science

Sideways Movement of the Neck

When the three dimensional models of the Nichollssaura borealis neck were examined the scientists discovered that the neck of this plesiosaur was indeed very mobile, but their results suggest a preference for lateral (sideways) movements of the neck in this species.  This supports the idea that these marine reptiles fed in or along the seafloor, using their small heads and long necks to probe into the sediment to find invertebrates and fish.

Unfortunately, no gut contents indicating potential prey have been preserved in association with the single fossil specimen of Nichollssaura, however, other researchers have found prey gut contents in other plesiosaurids that supports the idea that these animals fed by disturbing and catching animals that live on the sea floor (epifaunal).

To test the validity of the three-dimensional computer models, the scientists studied the range of neck movement in a extant species of monitor lizard, Dumeril’s monitor, a species from south-east Asia (Varanus dumerilii).  This species was chosen as it has a relatively long neck for a monitor lizard and a preserved specimen was available for study.

The researchers conclude that if this species of plesiosaurid (N. borealis) had a neck that was adapted to rapid sideways movements then this probably evolved in relation to feeding method and prey capture.  Different types of Plesiosauroidea with their different neck lengths very likely had different ecological roles within the ecosystem.  This study also demonstrates that three-dimensional modelling is an effective tool for assessing function morphology for structures where no good, living analogue for comparison exists.

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Sauropod Trackways Discovered in Dorset

Scientists have been measuring and mapping a set of dinosaur tracks found in a quarry in Dorset.  The saucer-shaped tracks were made by a herd of long-necked sauropod dinosaurs that crossed a stretch of a tidal lagoon back in the Early Cretaceous.  The quarry is located close to the village of Worth Matravers, around three-and-a half-miles east of the coastal town of Swanage, on the Isle of Purbeck.

A View (Dorsal) of a Dinosaur Footprint (Sauropoda)

Picture credit: Bournemouth University

Giant Dinosaur Tracks

The group of large dinosaurs were walking slowly in a herd, leaving a series of parallel trackways.  They have been described as “giant saucer-shaped depressions just a few millimetres deep”, according to geologist Matthew Bennett from Bournemouth University who has been called in to study and map the fossilised tracks.

The quarry is the property of Lewis Quarries, one of a number in the area that provide valuable limestone blocks for the construction industry.

An Aerial View of the Dinosaur Tracks

Picture credit: Bournemouth University

Early Cretaceous Dinosaur Tracks

The footprints were made between 139 and 145 million years ago (Early Cretaceous), the tracks were infilled by lime rich muds, creating trace fossils.

David Moodie, a spokesperson for Lewis Quarries explained:

“It became apparent that we had come across something of historical interest, so working closely with the National Trust and Professor Matthew Bennett of Bournemouth University, we were able to move forward in the best way without stopping progress in the quarry itself.”

National Trust Lead Ranger Jonathan Kershaw added:

“The group of dinosaurs that made these tracks may be the same ones whose footprints can still be seen in situ just nearby at Keates Quarry just off the Priest’s Way bridleway.  It’s exciting to think that giant sauropods once roamed where today there are dry stone walls, skylarks and nesting seabirds.”

An Illustration of the Sauropods Crossing the Shallow Lagoon

Picture credit: Bournemouth University

In 2015, Everything Dinosaur reported on the discovery of a series of sauropod footprints and tracks on the Isle of Skye.  These tracks were made in similar circumstances as the Purbeck limestone prints, a group of sauropods crossed a shallow lagoon, however, the Isle of Skye prints are around thirty million years older and date from the Middle Jurassic.

To read more about the sauropod prints from the Isle of Skye: Isle of Skye Sauropods and their Watery World.

DigTrace Maps the Fossil Footprints

Using a process of photogrammetry and special freeware developed at Bournemouth University called DigTrace, Professor Bennett carefully documented the tracks in three dimensions.  The DigTrace technology was developed with a government grant and help from the Home Office and National Crime Agency.  Its principle aim is to forensically examine footprints and other tracks related to crime scenes, however, it is ideal for plotting the movements of extinct dinosaurs too.

Professor Bennett commented:

“This technology is now being used by the police to help track criminals via their footprints, but we can also use it to record and preserve rare footprints like these.  The beauty of capturing the tracks in 3D is that they can be analysed digitally and even printed in the future, no need to hold up the quarrying for long.”

Drawing Up a Conservation Plan for the Dinosaur Tracks

With the co-operation of Lewis Quarries and in collaboration with the National Trust and researchers at Bournemouth University, a conservation plan is being prepared.  It is hoped that the tracks will be lifted from their setting and put on public display once all the appropriate scientific steps (pardon the pun), have been taken.

The trackway surface is also exposed in nearby Keates Quarry where the National Trust maintains a small conservation area of similar tracks.

Professor Bennett concluded:

“What is remarkable, is that the tracks at both adjacent quarries were probably made by the same animals moving along the coast.  The dip of the beds, folded when the European Alps were pushed up, means that the tracks are closer to the ground in Keates Quarry and can be preserved but are much deeper at Lewis Quarries where in situ preservation is not possible.”

The Dig Site at the Dorset Quarry

Picture credit: Bournemouth University

Everything Dinosaur acknowledges the assistance of the media centre at Bournemouth University for the compilation of this article.

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Akainacephalus johnsoni – One of the Oldest “Swingers” from North America

On Thursday of last week, a scientific paper was published in the on-line open access journal PeerJ, that described the discovery of a new species of armoured dinosaur from Utah.  The armoured dinosaur was named Akainacephalus johnsoni, the genus name is derived from the Greek meaning “spiky” or “thorn”, a reference to the large number of bony scales (caputegulae) located on the top and sides of the skull.  The species name honours Randy Johnson, a volunteer preparator at the Natural History Museum of Utah, who skilfully and patiently prepared the skull and lower jaws of this newly described ornithischian.

Akainacephalus johnsoni

A Close-up View of the Bony and Scaly Head of Akainacephalus

Picture credit: Andrey Atuchin (Denver Museum of Nature and Science)

Secondary Functions of the Dermal Armour

This was one very heavily armoured ankylosaurid, with a face described by many media outlets as “ugly” or being one that only a “mother could love”.  The fossilised skull, which is nearly complete reveals an extensive amount of armour and ornamentation.  For example, the snout is particularly bony, covered in large osteoderms and above each eye there is a substantial horn.  Although this armour would have served as protection against attack, the degree of ornamentation in Akainacephalus was quite remarkable, it is likely that these osteoderms, the various lumps and bumps on the dinosaur’s body and head, served a number of functions.

Suggested functions for the extensive ornamentation of A. johnsoni

• Anti-glare and anti-dazzle for the eyes.  If you look at the close-up view of the head of Akainacephalus in the illustration (above), the eye is shaded.  The various projections along the broad snout could have obscured the animal’s vision, but the eye would have been shaded from direct sunlight, a positive advantage in the Late Cretaceous of Utah.
• Sexual selection – the greater the ornamentation the more imposing the individual.  Just as with peacocks and their impressive tails, deer and their antlers, the greater the number of bumps and lumps could have been a sign of the animal’s fitness to mate.  It might be one very ugly looking dinosaur to us, but beauty is in the eye of the beholder, the lumpier the Akainacephalus the greater the appeal of that individual.
• In a similar vein to the point made above, the ornamentation could have played a role in display, intimidating rivals as part of ritualistic intraspecific combat or helping to put off the unwanted attentions of any large theropod that had decided to try and make a meal of this four-metre-long armoured dinosaur.
• Thermoregulation – the dermal armour of crocodilians serves a number of functions, one of which is to help to regulate the animal’s body temperature.  The wide gut of ankylosaurids gave them a large surface area for the sun to beat down onto.  By pumping blood into the osteoderms the animal could cool down, helping to maintain its body temperature.

Armoured Dinosaur Mixed Up with Lots of Other Fossils

The Fossil Remains of Akainacephalus and two Skeletal Reconstructions

Picture credit: PeerJ

The first fossils were found in 2008, in a quarry which contained a mixed assemblage of vertebrate remains.  Finds at the site, known as the Horse Mountain Gryposaur quarry, include a nearly complete skull of the hadrosaurid Gryposaurus, turtle fossil remains (Arvinachelys goldeni), a skull and postcranial remains of a new taxon of alligatoroid and a poorly preserved partial skull of a small theropod.

Akainacephalus Wanders Past Ancient Crocodilians

Picture credit: Andrey Atuchin (Denver Museum of Nature and Science)

The Amazing Kaiparowits Formation

The fossils were excavated from sediments associated with the Kaiparowits Formation, which provides a unique perspective on the biota of south/central Laramidia during the Campanian faunal stage of the Late Cretaceous.  This thick succession of sandstones and mudstones was deposited at an unusually rapid rate within a time frame of less than two million years, making it one of the most rapidly deposited terrestrial formations in the world.  Akainacephalus dates from 76.2 to 75.9 million years ago, as such it is one of the oldest ankylosaurids known from North America.

It is also the first documented example of ankylosaurid skull and postcranial bones from the Kaiparowits Formation.  Although, some of the fossil bones are in a better condition than others, the fossils, including that amazing tail club are remarkably complete.

Views of the Caudal Vertebrae and the Tail Club of A. johnsoni

Picture credit: PeerJ

Dinosaur Immigrants from Asia

Those lumps and bumps on the skull (cranial ornamentation), are reminiscent of an armoured dinosaur from New Mexico (Nodocephalosaurus kirtlandensis), the researchers postulate that these dinosaurs might be closely related.  However, it is worth noting that Nodocephalosaurus is around three million years younger than Akainacephalus.  Both Nodocephalosaurus and Akainacephalus are also similar to Asian ankylosaurids such as Saichania chulsanensis, Pinacosaurus grangeri, and the spectacularly horned Minotaurasaurus ramachandrani.   The discovery of Akainacephalus adds support to the idea that ankylosaurids migrated across an ancient land bridge from Asia into North America prior to 76 million years ago.

The addition of this new ankylosaurid taxon from southern Utah provides further information on ankylosaurid diversity and supports the theory regarding there being regional variations in dinosaur biota across Laramidia during the later stages of the Cretaceous.

Indicating that Ankylosaurids Migrated from Asia into North America (Akainacephalus johnsoni)

Picture credit: Andrey Atuchin (Denver Museum of Nature and Science)

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Baby Snake Preserved in Amber from Myanmar

A team of international researchers including scientists from the University of Alberta, Midwestern University and the Chinese Academy of Sciences have published a paper describing the remarkable discovery of the preserved remains of a baby snake entombed in amber from Myanmar (Burma). The snake has been named Xiaophis myanmarensis.

Amber deposits from northern Myanmar are providing scientists with some amazing insights into life in a forest some 100 million years or so ago.  Other amber nodules, known as burmite have revealed the preserved remains of baby birds, a dinosaur tail, frogs and an astonishing range of invertebrates and plant material.  The amber is proving to be a treasure trove for palaeontologists helping them to map the biota of a Cretaceous environment.

The Polished Amber Nodule Revealing the Fossilised Remains of a Baby Snake

Picture credit: Ming Bai (Chinese Academy of Sciences)

Xiaophis myanmarensis – Dawn Snake of Myanmar

The baby snake measures around eight centimetres in length.  The fossil reveals that the vertebrae are not yet fully formed and this indicates that the snake was very young when it got trapped in the sticky tree resin.  The snake has been named  Xiaophis myanmarensis, which means “dawn snake of Myanmar”.

The international research team, led by Dr Lida Xing (China University of Geosciences, Beijing and the Chinese Academy of Sciences) and Professor Mike Caldwell (University of Alberta), have described this discovery as a remarkable fossil find.

A Life Restoration of Xiaophis myanmarensis

Picture credit: Cheung Chung Tat

Not One Fossil Snake but Two

Although the baby snake is missing its skull, ninety-seven vertebrae have been preserved along with associated fossil ribs.  The tiny reptile’s bones were analysed using a synchrotron to bombard the specimen with X-rays and plot the result.  The back bone is remarkably similar to those found in neonatal snakes today.  This suggests that the vertebrae of snakes have remained largely unchanged for 100 million years.

A second amber fossil was discovered, which preserves a piece of the shed skin of another, much larger snake.  It is unclear whether these two fossils represent the juvenile and adult of the same species.

The Skeleton of the Baby Snake As Modelled from the Synchrotron Data

Picture credit: Ming Bai (Chinese Academy of Sciences)

Xiaophis myanmarensis – A Remarkable Fossil

The discovery of this remarkable fossil, along with the piece of shed snake skin helps palaeontologists to build a picture of the evolution of snakes and how they spread following the break-up of the super-continents during the latter stages of the Mesozoic.

Dr Palci (Flinders University) and a co-author of the scientific paper published in the journal “Science Advances” commented:

“At 100 million years old, it dates back to the age of the dinosaurs, well before snakes started to differentiate into modern groups.  This Asian fossil helps shed light on how primitive snakes dispersed from the southern to the northern continents.  Although found in the Northern Hemisphere, it strongly resembles South American snakes that lived at the time.”

An Illustration of the Second Snake Specimen (Life Reconstruction)

Picture credit: Yi Liu

During the Jurassic, the region that we now know as Myanmar was joined to Antarctica, Australia, Africa and South America, forming the giant, southern super-continent of Gondwana.  As the Mesozoic progressed so this landmass began to split apart, Myanmar separated from Gondwana and drifted north, eventually colliding with Asia.

This is the first baby snake fossil from the Mesozoic ever found and it, along with other remarkable specimens preserved in amber from Myanmar (burmite), are providing scientists with a unique window into the Late Cretaceous world.

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Fossil Discovery Hints at Spanish Elasmosaurid

Recently printed in the academic journal “Cretaceous Research”, a trio of scientists have published details about a new plesiosaur specimen discovered in Late Cretaceous sediments in Guadalajara Province in central Spain.  Plesiosaur specimens are exceptionally rare from the Late Cretaceous of Europe and although the fossil material is indistinct in terms of any autapomorphies (unique features), that would permit the establishment of a new species, the fragmentary fossils, including a single tail bone, represent an important discovery nonetheless.

An Illustration of a Typical Member of the Plesiosauridae

Picture credit: Everything Dinosaur

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The First Plesiosauria from Algora

The fossils consist of elements from a pelvic girdle and a caudal vertebra (tail bone).  They are the first evidence of a plesiosaur in the coastal marine outcrops of Algora (Castilla-La-Mancha), Spain.  It is one of only a handful of such specimens reported from the Cretaceous of Spain.

The Pelvic Girdle Fossil Bones with an Accompanying Line Drawing

Picture credit: N. Bardet, M. Segura and A. Pérez-García/Cretaceous Research

An Elasmosaurid

The fossils probably represent a single individual, as such, it is the only plesiosaur specimen from central Spain that is known from several bones.  The researchers conclude that the material represents an indeterminate member of the Elasmosauridae.  Elasmosaurids were a type of plesiosaur that had a wide geographical range during the Late Cretaceous and one that persisted to the end of the Maastrichtian faunal stage.

Views of the Caudal Vertebra (Indeterminate Elasmosaurid)

Picture credit: N. Bardet, M. Segura and A. Pérez-García/Cretaceous Research

The authors of the scientific paper include a researcher from the Natural History Museum of Paris (Muséum National d’Histoire Naturelle), as well as two researchers based in Spain.  They suggest that the fossils represent an individual that either died further out to sea and was washed into a bay (thanatocoenosis), or the remains of an animal that lived in a near-shore environment (biocoenosis).

The scientific paper: “A Plesiosaur (Reptilia, Sauropterygia) from the Cenomanian (Late Cretaceous) of Algora (Guadalajara Province, Central Spain)” by N. Bardet, M. Segura and A. Pérez-García published in Cretaceous Research.

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