Prehistoric “Polly” Challenges View on Ancient Parrot Radiation and Dispersal

A partial tarsometatarsus bone from Siberia proves that ancient parrots lived much further north in the past.  This fragment of fossil parrot bone, dating from around 18-16 million years ago was discovered in the Lake Baikal region of Siberia.

Fossil Parrot Bone

This is the first time parrot fossils have been found in Siberia or the whole of Asia for that matter.  Parrots are mostly confined to the tropics and sub-tropics of our world today.  The parrots (Order Psittaciformes), are represented by nearly 400 hundred species and they are found throughout Africa, Asia, Australasia and the New World.  This fossil discovery, a single bone that measures around half a centimetre in length has challenged the view that parrots spread into the New World by crossing the Atlantic from Africa.

Another route will have to be considered, a movement east across the northern latitudes of Siberia and down into the New World from Alaska.

The Fragment of Fossil Bone Compared to Extant Specimens

The prehistoric tarsometatarsus fossil compared to other parrot specimens (extant).

Picture credit: Dr Nikita Zelenkov (Borissiak Palaeontological Institute of the Russian Academy of Sciences) with additional annotation by Everything Dinosaur

The picture above shows the tiny fragment of the tarsometatarsus of the Miocene parrot (a, e, i, j, k) compared to other fossil specimens and tarsometatarsus bones from extant species.

Key

_ = specimen number PIN 2614/218 Early Miocene of Tagay (eastern Siberia)

_ = tarsometatarsus of the Yellow-Tailed Black Cockatoo (from Australia) Calyptorhynchus funereus

_ = tarsometatarsus of the Cuban Parakeet (Aratinga euops)

_ = tarsometatarsus of the Black-capped Lory (Lorius lory) of New Guinea

Psittaciformes Dispersal Routes

The fossil was discovered at Tagay Bay, Olkhon island (Lake Baikal) in the Irkutsk Region of Eastern Siberia, Russia.  This location (Khalagay Formation), has yielded a number of Early Miocene vertebrate fossils including rodents, members of the rhino family, hippos and cats.  The deposits are also famous for the number of bird fossil specimens found.  It is the only location in Asia where Early Miocene Aves fossils have been found.  Author of the scientific paper, describing this discovery, Dr Nikita Zelenkov of the Borissiak Palaeontological Institute of the Russian Academy of Sciences explained the significance of this fossil:

“This locality is also interesting because it preserves a rich community of fossil birds.  But no exotic birds have been found there before.  Unfortunately, this find is not good enough to reconstruct the appearance or lifestyle of this parrot, but we can see that it was rather similar to modern ones.  So, it was likely a very modern-looking small bird, around the size of a budgerigar.”

For models and replicas of Miocene creatures and other extinct animals: Wild Safari Prehistoric Animal Models.

Links to a Fossil Parrot Bone Found in Germany

It shares features with another earlier fossil parrot bone in Germany, reported in a study published in 2010, belonging to a species called Mogontiacopsitta miocaena.  However, no parrot fossils have been found this far north before, or indeed in Asia.  This suggests that parrots may have spread to the New World via an eastern route rather than flying across the Atlantic from Africa, a hypothesis favoured by many palaeontologists until the unearthing of this new fossil evidence.

A Map Showing the Old World Distribution of Psittaciformes and Parrot Fossil Finds

Old World parrot distribution and fossil finds from Europe and Asia.

Picture credit: Biology Letters

The map above shows current Old World distribution of parrots (black area), Miocene finds of parrots in Europe including Mogontiacopsitta (white stars) and the position of Tagay locality (black star) where the tarsometatarsus fragment was found.

What is a Tarsometatarsus?

To a vertebrate palaeontologist, the tarsometatarsus is a very important bone.  It is a relatively long, lower leg bone found only in the skeletons of birds and certain types of dinosaur.  It is fully fused in modern birds although, in prehistoric bird types, the fusion is somewhat different and far from complete, for example in the enantiornithines, a diverse group of Mesozoic birds that died out at the end of the Cretaceous, the bones that form the tarsometatarsus were only partially fused along their length.  The bones that make up the tarsometatarsus are represented by the ankle and toe bones (metatarsals) in mammals and other types of archosaur.

The scientific paper (Biology Letters): “The First Fossil Parrot (Aves, Psittaciformes) from Siberia and its Implications for the Historical Biogeography of Psittaciformes.”

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Titanosaur Trace Fossils Excite Palaeontologists

Now that team members have published an article on Australia’s newest titanosaurid (Savannasaurus elliottorum), we can turn our attention to another scientific paper, actually published last month, which details an exciting titanosaur related discovery but this time from Europe, or to be more precise Catalonia in Spain.  Researchers have discovered fossils of skin impressions in rocks that were formed from sediments deposited at the very end of the Age of Dinosaurs.

A Close View of the Larger of the Two Dinosaur Skin Impression Fossils

Titanosauriform sauropod dinosaur skin impression (Catalonia).

Picture credit: Universitat Autònoma de Barcelona (Autonomous University of Barcelona)

How was the Titanosaur Skin Impression Made?

The picture above shows the bigger of the two dinosaur trace fossils.  Large, irregular, quite angular scales can be made out.

However, what the photograph shows is not the actual skin impression but a natural cast. Sometime around 66 million years ago a dinosaur was crossing a stretch of mud close to a river.  It may have slipped and fallen or perhaps it simply rested for a while lying down on the sticky muddy surface.  An impression of the animal’s scales was made in the soft mud.  These marks were later covered by sand, perhaps as a result of the river level rising.

Over tens of thousands of years, this sand was slowly turned to sandstone (sedimentary rock).  Uplift and subsequent erosion exposed the rock layer where the natural cast was preserved and over time the softer mudstone was gradually eroded away leading to the exposure of the natural cast of the dinosaur’s skin.

Trace fossils such as this preserve a moment in time, they preserve evidence of behaviour or activity.  If you look carefully you can see shadows around some of the individual scales, the scales are raised.  This sort of trace fossil is known as an epirelief (raised) fossil.

How Do We Know the Fossils Come from a Titanosaur?

In truth, nobody knows for certain what type of animal left these impressions of its skin.  The shape of the scales are similar to other dinosaur skin impressions, so it is very likely that these fossils represent a member of the Dinosauria.  The size of the individual scales are just too big for the theropod and ornithopod dinosaurs that are known to have lived in this area some sixty-six million years ago.

In addition, palaeontologists have found the big, rounded tracks of wide-bodied titanosaurs in similar-aged strata close by.  So, in all probability, these two fossils represent a titanosaur and it is likely that the two epirelief trace fossils, one about twenty centimetres wide and the other just five centimetres across and within one and a half metres of the other, were made by the same animal at the same time.

For models and replicas of titanosaurs and other dinosaurs: CollectA Deluxe Prehistoric Animal Replicas and Models.

Titanosaur Has a Lie Down

A titanosaurid takes a rest on a riverbank.

Picture credit: Mark Witton (with some background alteration by Everything Dinosaur)

The Last European Dinosaurs

Universitat Autònoma de Barcelona researcher and lead author of the scientific paper published in the “Geological” magazine, Victor Fondevilla, explained that although dinosaur skin impressions have been discovered in Europe before, they don’t come from the very end of the Mesozoic.

He stated:

“This is the only registry of dinosaur skin from this period in all of Europe, and it corresponds to one of the most recent specimens, closer to the extinction event, in all of the world.”

These trace fossils, located in the red sandstone beds of the Tremp Formation (southern Pyrenees), represent some of the most recent dinosaur fossils ever made, coming from the chronozone associated with the period of the Maastrichtian faunal stage immediately before the K-Pg extinction event.  These, in situ titanosaur fossils come from C29r chronozone or chron, as these slices of time are sometimes referred to.  Thus, they represent some of the last fossils known representing titanosauriforms.

Victor Fondevilla Points out Where the Larger of the Two Trace Fossils can be found on the Exposed Rock Face

Looking at dinosaur skin fossils.

Picture credit: Universitat Autònoma de Barcelona (Autonomous University of Barcelona)

The Scientific paper: “Skin Impressions of the Last European Dinosaurs” published in Geological Magazine (Cambridge University Press).

Visit Everything Dinosaur’s website: Everything Dinosaur.

To read our article on “Wade” Savannasaurus elliottorum: Titanosaurs Crossing Continents.