Inspiring Ichthyornis – Top of the Pecking Order

As a very young boy, I remember eagerly striving to complete my Brooke Bond “Prehistoric Animals” card collection.  This was a set of fifty cards to collect,  given away free with packets of tea.   One of the cards featured a pair of toothed, prehistoric birds, a large, reddish coloured Hesperornis which was being mobbed by a couple of tern-like birds, this was my first introduction to Ichthyornis.  Perhaps, the first time that I realised that birds (at least primitive, toothed birds), lived alongside dinosaurs.

How wonderful to read this week that Ichthyornis, thanks to a pieced together three-dimensional skull, may be providing palaeontologists with fresh insights into avian evolution.  The Hesperornis/Ichthyornis picture card may have been burned into my conscience long ago, but it is refreshing to think that this ancient bird may represent a pivotal moment in the transition from dinosaurs to modern-day birds and its significance has only just come to light.  A team of international scientists have published a paper proposing that Ichthyornis may have had one of the first, true bird-like beaks.

The Brooke Bond Picture Card

Picture credit: Everything Dinosaur/Brooke Bond

Toothy Bird with the Beginnings of a Beak

Writing in the journal “Nature”, researchers report on the analysis of beautifully preserved three-dimensional Ichthyornis (I. dispar) fossil skull that is providing new evidence on the evolution of the avian head and how the skull and beaks of birds evolved from their dinosaurian ancestors.

A Three-Dimensional Image of Ichthyornis Skull Material Indicates the Tip of the Premaxillary Formed the First Beak

Picture credit: Yale Office of Public Affairs and Communications

Ichthyornis dispar

Known from fragmentary fossils from Kansas and named back in 1872 by Yale University’s Othniel Charles Marsh, it seems fitting that this new study into one of the first toothed birds described, has been led by scientists from Yale University.  Working in conjunction with colleagues from the University of Kansas, Fort Hays State University, Alabama Museum of Natural History and the McWane Science Centre (Alabama), the team report on new specimens with three-dimensional cranial remains, including one example of a complete skull and two previously overlooked cranial elements that were part of the original Yale specimen examined by Marsh.

Using CT scans and sophisticated computer modelling, individual skull and jaw bones were scanned and reproduced in three-dimensions.  This allowed a complete skull to be constructed revealing new details about the transition from dinosaur skull to a more modern bird skull.

The Transition from Dinosaur Skull to Bird Skull

Yale University palaeontologist and lead author of the study Bhart-Anjan Bhullar commented:

“Right under our noses this whole time was an amazing, transitional bird.  It has a modern-looking brain along with a remarkably dinosaurian jaw muscle configuration.”

Ichthyornis is part of the biota of the Western Interior Seaway, a shallow sea that split North America in two during the Late Cretaceous.  It has been regarded as an early version of a tern or gull, but its size is unknown as the few fossils found represent individuals of different sizes, however, it probably had a wingspan of no more than sixty centimetres, making Ichthyornis slightly smaller than today’s Common Tern (Sterna hirundo), a bird which fills the same ecological niche as the Mesozoic Ichthyornis.

Using the Latest Research, a New Reconstruction of Ichthyornis dispar was Produced

Picture credit: Yale Office of Public Affairs and Communications

Ichthyornis – The Evolution of a Beak

Having built a three-dimensional model of the skull and jaw bones, the researchers were able to note that the premaxillary bone in the upper jaw had become elongated and this, working in conjunction with a keratinous tip on the lower jaw formed the first “proto-beak”.  Ichthyornis dispar shows scientists what the first type of bird beak looked like.  This beak may have evolved as the function of the hands was increasingly limited as they were adapted to form a more effective wing.

The grasping hands of the maniraptoran dinosaurs were no longer able to grasp and manipulate objects so the jaws had to take on an additional function, secondary to their main function – dispatching and consuming prey.

The Beak of Ichthyornis

Picture credit: Yale Office of Public Affairs and Communications

Although maniraptoran dinosaurs may not have been able to pronate their hands like us and they lacked an opposable thumb, as forelimbs and hands evolved into wings, so the jaws took over the function of the digits and manus.

Bhart-Anjan Bhullar stated:

“The first beak was a horn-covered pincer tip at the end of the jaw.  The remainder of the jaw was filled with teeth.  At its origin, the beak was a precision grasping mechanism that served as a surrogate hand as the hands transformed into wings.”

The research team conducted its analysis using CT-scan technology, combined with specimens from the Yale Peabody Museum of Natural History; the Sternberg Museum of Natural History in Hays, Kansas, the Alabama Museum of Natural History; the University of Kansas Biodiversity Institute and the Black Hills Institute of Geological Research (South Dakota).

Bird Beaks versus Bird-hipped Dinosaur Beaks

The modern bird beak is a unique organ amongst vertebrates, although notably most derived ornithischian (bird-hipped) dinosaurs possessed a beak, formed from the unique predentary bone in the lower jaw and a roughened, extension of the premaxilla (or the rostral in the case of ceratopsians), in the upper jaw, which allowed the attachment of a keratinous tip which in conjunction formed the beak-like structure – believed to be an adaptation to assist with cropping vegetation.

This study of Ichthyornis suggests that the first bird beak was not the long organ seen in modern birds, but a little pincer tip to grasp and manipulate objects.

A Chasmosaurine Ceratopsian with the Roughened Rostral and the Predentary Forming a Plant-cropping Beak

The picture (above) shows a ceratopsian figure from the PNSO model range.

To view these figures: PNSO Age of Dinosaurs Models.

Fresh Insight into the Evolution of Extant Bird Skulls

The scientists conclude that their study offers new insights into how modern birds’ skulls formed.  Along with its transitional beak, Ichthyornis dispar had a brain similar to that seen in extant birds but a temporal region of the skull that was reminiscent of a dinosaur.  This suggests that during the evolution of Aves, the brain transformed first, possibly to adapt to a volant (aerial) lifestyle, whilst the remainder of the skull retained the ancestral features associated with the Dinosauria.

Ichthyornis retained a large adductor chamber bounded at the top by substantial bony remnants of the ancestral reptilian upper temporal fenestra (hole in the skull).  This combination of features indicates that important attributes of the avian brain and palate evolved before the reduction of jaw musculature and the full transformation of the beak.

The Beak of Ichthyornis Grasping a Mollusc

Picture credit: Michael Hanson/Bhart-Anjan Bhullar

I may never have completed my Brooke Bond card collection, but at least, thanks to this new Ichthyornis study, our understanding of the evolution of the beak in birds is more complete.

Visit the Everything Dinosaur website: Everything Dinosaur.

Pathology Identified in Lufengosaurus Specimen

An analysis of a 200 million-year-old bite-mark has provided scientists with a detailed picture of a dinosaur’s life.  The bite-mark, preserved on the fossilised rib of a Lufengosaurus (L. huenei) may also provide a clue to how this member of the Sauropodomorpha met its end.  The specimen preserves evidence of an attack on a plant-eating dinosaur, probably from a theropod and although the attack initially was not fatal, the resulting infection that occurred in the bone may have contributed to the unfortunate dinosaur’s death.

A Life Reconstruction of the Lufengosaurus Showing the Bitemark

Picture credit: Zongda Zhang

Studying Lufengosaurus

Employing an advanced X-ray technique, an international team of scientists from the UK, China, the United States and South Africa, have published evidence for an unsuccessful attack on a Jurassic dinosaur, a member of the Suborder Sauropodomorpha from China known as Lufengosaurus (L. huenei).  Everything Dinosaur was contacted by one of the authors of the scientific paper, published in the academic journal “Nature Scientific Reports”, a PNSO Lufengosaurus replica was purchased so that the model could be used to help explain the pathology and inferred animal behaviour from the scientific research.

The study provides a detailed report of the first recognised case of an abscess in a long-necked dinosaur from the Lower Jurassic of China, (Yunnan Province), which was caused by infection brought on from the bite of a large predatory dinosaur.  The infection may have weakened the animal, ultimately resulting in its death.

Scientist Lida Xing Holding the Damaged Rib Bone

Picture credit: Lida Xing

Micro-computed X-ray Tomography

The pathology, was discovered in the skeleton of a L. huenei, which is part of the vertebrate fossil collection at the Yuxi Museum (Yunnan Province).  The fossil rib bone was subjected to micro-computed x-ray tomography (micro-CT).   This permits high-resolution slices and three-dimensional images to be built up of internal structures of bone without damaging the fossil material.

It is a non-destructive research technique.  As well as providing detailed evidence of interactions between big, herbivorous dinosaurs and carnivorous theropods, the successful identification of this abscess using this technique could point to a new understanding of where certain species lived, and the impact of the diseases that they suffered from.

Studying Fossil Rib Pathology

Commenting on the significance of the research, one of the authors of the scientific paper, Dr Patrick Randolph-Quinney (University of Central Lancashire in the UK and the University of the Witwatersrand in South Africa), stated:

“We were able to use micro-CT to look deep inside the structure of the rib and visualise the precise changes that bacterial infection had caused, as well as to see the region of bone that had been bitten out of the rib.  What micro-CT is allowing us to do is understand processes such as trauma and infection in the fossil record at the cellular level, as well as looking at the whole bone.” 

Dr Randolph-Quinney continued:

“This gives us advantages over traditional histology – which slices up bone for magnification under a microscope – in that it doesn’t require us to damage precious fossils and it also allows us to build 3-D reconstructions of the whole region of disease.  In this case, this has allowed us to model and study the whole wound track, not just a single portion of it.”

Images of the Rib Pathology

Picture credit: Patrick Randolph-Quinney (University of Central Lancashire)

The picture (above), shows a 3-D and 3-D slice reconstruction of the Lufengosaurus rib pathology.  Micro-computed tomography allowed the scientists to produce surface renderings of the fossil in 3-D (top row) and 2-D X-ray slices through the rib (bottom row).  These images show areas of cellular reorganisation, bone destruction and bone formation indicative of ostemyelitis (bone infection).

Lufengosaurus (L. huenei)

Lufengosaurus grew to about six metres in length.  It is estimated to have weighed around two tonnes.  More than two dozen specimens of this prosauropod have been discovered to date, adults as well as fossil material from juveniles.  All the fossils ascribed to this genus have been discovered in the Lufeng Formation of south-western China (Yunnan Province).  Yang Zhongjian, known in western literature as Chung Chien Young, formally named and described Lufengosaurus in 1941.  Lufengosaurus was the first dinosaur from China to have been discovered, studied and displayed by Chinese scientists.

The PNSO Lufengosaurus Dinosaur Model Supplied to the Researchers by Everything Dinosaur

Picture credit: Everything Dinosaur

The image (above) shows a PNSO Lufengosaurus dinosaur model.

To view the PNSO range of prehistoric animals: PNSO Age of Dinosaurs.

Lead author of the study, Dr Lida Xing (China University of Geosciences) added:

“This case is really exciting as it gives us evidence of interactions between large plant-eating dinosaur species and one of the large aggressive predators preying on them at that time.  Using the latest X-ray imaging we were able to track the changes in the bone caused by an infected bite on the Lufengosaurus, probably from a big carnivorous dinosaur.  We don’t just have evidence of disease but of behaviour between animals – between predator and prey at this deep period in prehistory.”

An International Team of Researchers

This study was carried out by researchers at the University of Central Lancashire (UCLan), China University of Geosciences, the University of the Witwatersrand in South Africa, the Carnegie Museum of Natural History in the USA, the State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, and the Yuxi Museum, Yunnan, China.

The team were able to identify an infection in the bone called osteomyelitis which produces a pus-filled abscess inside the bone.  This is only the second time that a case of osteomyelitis has been recorded in the Sauropodomorpha, the other instance came from a giant titanosaur from Argentina, the Lufengosaurus example pre-dates the Argentinian example by tens of millions of years.  It is the earliest recorded case of a bony abscess caused by osteomyelitis disease in the fossil  record.

Views of the Damaged Lufengosaurus Rib Bone

Picture credit: Lida Xing

Clinical Science and Palaeontology

Hao Ran from the Kunming Institute of Zoology, Chinese Academy of Sciences, commented:

“This is a great example of how the clinical sciences and the science of palaeontology are working together with fossils from the Chinese fossil record.  Together with international collaborators we are able to advance our understanding of diseases in both the past and the present.  We don’t know which predator caused the bite, but we do have a smoking gun of the attack with the bite wound it left.”

The scientific paper: “Possible Bite-induced Abscess and Osteomyelitis in Lufengosaurus (Dinosauria: Sauropodomorph) from the Lower Jurassic of the Yimen Basin, China” by Lida Xing, Bruce M. Rothschild, Patrick S. Randolph-Quinney, Yi Wang, Alexander H. Parkinson and Hao Ran published in Nature Scientific Reports.

Visit the Everything Dinosaur website: Everything Dinosaur.