The First Duckbill from Africa

Fragmentary fossils including parts of a jawbone have led an international team of scientists to announce the discovery of a new species of dinosaur from the Late Cretaceous of Morocco.  A number of dinosaurs have been described from the marine sediments that comprise the economically important phosphate deposits associated with  the Ouled Abdoun Basin of north-central Morocco, but this new discovery is of particular significance.  These are the first fossils of a hadrosaur known from Africa and it suggests that these duck-billed dinosaurs were capable of crossing hundreds of miles of open ocean to reach new habitats.  The lambeosaurine dinosaur has been named Ajnabia odysseus.

A Life Reconstruction of the Newly Described Lambeosaurine Ajnabia odysseus

Picture credit: Raul Martin

Ajnabia odysseus – A Lambeosaurine Hadrosaur

The genus name means stranger or foreigner in Arabic, a reference to the fact that these ornithischian dinosaurs were not known from Africa.  The species name is a reference to Odysseus the sea-faring hero of Homer’s epic poem “Odyssey”.  The researchers which include Dr Nicholas Longrich (University of Bath) and Professor Nour-Eddine Jalil  from the Department of Geology (FSSM), at the University Cadi Ayyad (Morocco), comment that this dinosaur lived about a million years before the end-Cretaceous extinction event (Late Maastrichtian).

A phylogenetic assessment suggests that Ajnabia was closely related to European hadrosaurs (the Arenysaurini, a clade of lambeosaurines previously known only from France and Spain).

The teeth and jawbone permitted the scientists to assign it to the lambeosaurine branch of the Hadrosauridae, a group of duck-billed dinosaurs famed for their elaborate and ornate hollow crests.  It is very likely that the lambeosaurine dinosaurs evolved in North America and then spread into Asia via a northern land bridge before moving into Europe and finally crossing deep and wide seas to reach North Africa.

The specimen suggests that this dinosaur was a dwarf when compared to its more famous and geologically older relatives from North America such as Corythosaurus, Parasaurolophus and Lambeosaurus.  The research team estimate the Ajnabia was around three metres long.

A Scale Drawing of the Newly Described Moroccan Lambeosaurine A. odysseus

Picture credit: Everything Dinosaur

Distinct Dinosaur Dominated Terrestrial Faunas

By the Late Cretaceous distinct dinosaur dominated terrestrial faunas had been established in the Northern and Southern Hemispheres.  This had been driven by the continued break-up of the landmass that once was the super-continent Pangaea, the widening of the Atlantic and a rise in global sea levels.

The Northern Hemisphere dinosaur biota was characterised by duck-billed dinosaurs, the Ceratopsia (horned dinosaurs) with tyrannosaurids occupying the niche of apex predators.

The Southern Hemisphere dinosaur biota was characterised by the continuation of the titanosaurian sauropods with members of the Abelisauridae as top predators.

The scientists conclude that hadrosaurs must have crossed hundreds of miles of ocean to rich Africa.  These plant-eating dinosaurs with their powerful, deep tails were very probably capable swimmers so such feats may not have been beyond them.  After all the estuarine crocodile (Crocodylus porosus), has been known to cross wide stretches of open water and has been spotted far out to sea.

Perhaps, dinosaurs were swept out to sea on rafts of vegetation following a storm event, which permitted them to colonise new habitats.

A Modern Analogy – Iguanas on the Island of Anguilla

Green iguanas were found to be living on the Caribbean island of Anguilla when they had not been reported from the island before.   Biologists concluded that hurricanes in 1995 had led to trees that originated in Guadaloupe some two hundred miles to the south-east of Anguilla, where the iguanas are indigenous, being washed ashore.  It is thought that a group of these reptiles drifted out to sea and after about three weeks, the trees, with their unintentional lizard cargo made landfall on the island.

An Unlikely Seafarer – An Iguana

Picture credit: Everything Dinosaur

Dr Longrich commented:

“Over millions of years, once-in-a-century events are likely to happen many times.  Ocean crossings are needed to explain how lemurs and hippos got to Madagascar, or how monkeys and rodents crossed from Africa to South America.”

Ajnabia odysseus Colonised New Territories

Writing in the academic journal “Cretaceous Research”, the scientists conclude that as there were extensive and long-lasting seaways separating Africa and Europe from other landmasses and in the absence of any evidence for a two-way faunal interchange characterised by land bridges, it is likely that some animals were able to colonise new territories either by swimming to them or perhaps by being castaways.  Such patterns of dispersal are seen with both extant or ancestral forms of mammals, reptiles and amphibians.  This newly published paper suggests that dinosaurs too, were capable of travelling across oceans.

Dr Longrich added:

“As far as I know, we are the first to suggest ocean crossings for dinosaurs.”

Co-author Professor Nour-Eddine Jalil summarised the importance of this fossil find from a Moroccan phosphate mine by stating:

“The succession of improbable events (crossing an ocean by a dinosaur, fossilisation of a terrestrial animal in a marine environment) highlights the rarity of our find and therefore its importance.  Ajnabia shows us that hadrosaurs have set foot on African land, telling us that ocean barriers are not always an insurmountable obstacle.”

The scientific paper: “The first duckbill dinosaur (Hadrosauridae: Lambeosaurinae) from Africa and the role of oceanic dispersal in dinosaur biogeography” by Nicholas R. Longrich, Xabier Pereda Suberbiola, R. Alexander Pyron and Nour-Eddine Jalil, published in Cretaceous Research.

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Buriolestes schultzi – A Relatively “Smart” Sauropodomorph

The huge sauropods such as Apatosaurus, Brachiosaurus, Mamenchisaurus and Brontosaurus are not regarded as particularly clever animals.  Their brains were extremely small when compared to their huge body sizes, therefore any consideration of a “smart” sauropod is greatly undermined by their miniscule encephalisation quotient (ratio of brain size to body size).  However, this lineage of lizard-hipped dinosaurs survived for over a 130 million years and they were extremely successful being both speciose and geographically widespread.

A newly published paper provides an insight into the evolutionary development of the brains of these types of dinosaurs.  Writing in the academic “Journal of Anatomy” scientists report upon the study of the near perfectly preserved neurocranium of Buriolestes schultzi, a member of the Sauropodomorpha known from the Carnian faunal stage of the Late Triassic of Brazil.  The researchers conclude that although the brain of this emu-sized dinosaur was very small, it probably had acute vision and fast reactions – very useful when you are actively pursuing prey.

A Life Reconstruction of the Triassic Sauropodomorph Buriolestes schultzi

Picture credit: Márcio L. Castro

A Well-developed Flocculus of the Cerebellum

Buriolestes roamed what is now the Rio Grande do Sul region of southern Brazil around 233 million years ago.  It was a lightweight, bipedal, omnivorous dinosaur part of a group whose descendants would evolve into the giant sauropods of the Jurassic and Cretaceous.  Researchers from the Federal University of Santa Maria in collaboration with colleagues from the Universidade de São Paulo (both institutions in Brazil), used computerised tomography to create a three-dimensional landscape of the inside of the skull of a fossil specimen in order to map the various regions of the brain.

They discovered that Buriolestes had a well-developed flocculus region of its cerebellum, a part of the brain linked to motor skills and co-ordination.  The analysis also revealed an elongated olfactory tract (related to sense of smell), combined to a relatively small pituitary gland, but the area of the brain associated with processing information from the eyes was much more sophisticated.  The researchers inferred that the eyes were essential in the pursuit of prey, that vision was the dominant sense of Buriolestes.

Mapping the Brain of a Late Triassic Sauropodomorph (B. schultzi)

Picture credit: Márcio L. Castro

The Senses of Buriolestes

Commenting on the research, one of the co-authors of the paper, palaeontologist Mario Bronzati (Universidade de São Paulo), stated:

“The dinosaur [Buriolestes] had a faunivorous diet.  Unlike a carnivore, which is restricted to eating meat from other animals, the faunivore also includes the ingestion of insects and other small invertebrate animals.  This characteristic, as well as its size, makes the species quite different from the most famous representatives of its lineage, the sauropod giants and herbivores which were the largest animals ever to walk the Earth.”

The team concluded that the characteristics of the brains of these types of dinosaurs changed dramatically as they evolved an entirely herbivorous diet and developed huge body sizes.  Whilst Buriolestes was an agile, swift hunter the later sauropods evolved brains more suited to their particular niche in dinosaur dominated terrestrial communities.

Jurassic sauropods such as Brontosaurus and Diplodocus had higher olfactory capabilities when compared to Buriolestes.   This more developed sense of smell is believed to play a role in foraging, helping plant-eaters to discriminate between digestible and indigestible vegetation.  Having a better sense of smell may also have been important in the later sauropods if they were social animals living in herds.  For example, higher olfactory capabilities are associated with vertebrates with more complex social behaviours, it is important for these herding animals to be able to detect and track chemical secretions.

First Calculations of the Reptile Encephalization Quotient (REQ) for a Triassic Dinosaur

As well as providing information on how the brains sauropodomorphs evolved and changed over time, the researchers were able to plot the Reptile Encephalisation Quotient (REQ) for Buriolestes, the first time this has been calculated for a Triassic dinosaur.  The Reptile Encephalisation Quotient essentially correlates an animal’s physical characteristics with perceived intelligence, it provides an estimate of how “smart” an animal might be.

Time‐calibrated Reptile Encephalisation Quotient (REQ; 50%) of Selected Saurischians

Picture credit: Müller et al (Journal of Anatomy)

The scientists found that B. schultzi had a REQ lower than most Jurassic theropod dinosaurs, but much higher than that of later, much larger sauropodomorphs.  Although, the lack of fossils to study prevents the researchers from comparing the REQ of Buriolestes with contemporaneous animals, the team do suggest that when Jurassic sauropods are considered, it could be that encephalisation tended to decline in this dinosaur lineage.

To read an early article (2016) about Buriolestes by Everything Dinosaur: When Did the Dinosaurs Dominate the Land?

The scientific paper: “The endocranial anatomy of Buriolestes schultzi (Dinosauria: Saurischia) and the early evolution of brain tissues in sauropodomorph dinosaurs” by Rodrigo T. Müller, José D. Ferreira, Flávio A. Pretto, Mario Bronzati and Leonardo Kerber published in the Journal of Anatomy.

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