An unassuming brown pebble, found more than a decade ago by a fossil hunter in Sussex, has been confirmed as the first example of fossilised brain tissue from a dinosaur.
The fossil, most likely from a species closely related to Iguanodon, displays distinct similarities to the brains of modern-day crocodiles and birds. Meninges - the tough tissues surrounding the actual brain - as well as tiny capillaries and portions of adjacent cortical tissues have been preserved as mineralised 'ghosts'.
The results are reported in a Special Publication of the Geological Society of London, published in tribute to Professor Martin Brasier of the University of Oxford, who died in 2014. Brasier and Dr David Norman from the University of Cambridge co-ordinated the research into this particular fossil during the years prior to Brasier's untimely death in a road traffic accident.
The fossilised brain, found by fossil hunter Jamie Hiscocks near Bexhill in Sussex in 2004, is most likely from a species similar to Iguanodon: a large herbivorous dinosaur that lived during the Early Cretaceous Period, about 133 million years ago.
Finding fossilised soft tissue, especially brain tissue, is very rare, which makes understanding the evolutionary history of such tissue difficult. "The chances of preserving brain tissue are incredibly small, so the discovery of this specimen is astonishing," said co-author Dr Alex Liu of Cambridge's Department of Earth Sciences, who was one of Brasier's PhD students in Oxford at the time that studies of the fossil began.
A specimen of Rhamphorhynchus with soft tissue preservation, stomach contents and a putative coprolite
Authors:
Hone et al
Abstract:
Despite being known for nearly two centuries, new specimens of the derived non-pterodactyloid pterosaur Rhamphorhynchus continue to be discovered and reveal new information about their anatomy and palaeobiology. Here we describe a specimen held in the collections of the Royal Tyrrell Museum of Palaeontology, Alberta, Canada that shows both preservation and impressions of soft tissues, and also preserves material interpreted as stomach contents of vertebrate remains and, uniquely, a putative coprolite. The specimen also preserves additional evidence for fibers in the uropatagium.
Researchers from North Carolina State University have confirmed that blood vessel-like structures found in an 80 million-year-old hadrosaur fossil are original to the animal, and not biofilm or other contaminants. Their findings add to the growing body of evidence that structures like blood vessels and cells can persist over millions of years, and the data not only confirm earlier reports of protein sequences in dinosaurs, they represent a significant advance in methodology.
Molecular paleontologist Tim Cleland, currently a postdoctoral researcher at the University of Texas at Austin, began the work while a graduate student at NC State. He demineralized a piece of leg bone from a Brachylophosaurus canadensis, a 30-foot-long hadrosaur that roamed what is now Montana around 80 million years ago. Cleland analyzed the demineralized bone with high resolution mass spectroscopy and found several distinct proteins from the cellular components of the blood vessels. One of these proteins, myosin, is found in the smooth muscles associated with the walls of blood vessels.
Preservational Pathways of Corresponding Brains of a Cambrian Euarthropod
Authors:
Ma et al
Abstract:
The record of arthropod body fossils is traceable back to the “Cambrian explosion,” marked by the appearance of most major animal phyla. Exceptional preservation provides crucial evidence for panarthropod early radiation. However, due to limited representation in the fossil record of internal anatomy, particularly the CNS, studies usually rely on exoskeletal and appendicular morphology. Recent studies [ 1–3 ] show that despite extreme morphological disparities, euarthropod CNS evolution appears to have been remarkably conservative. This conclusion is supported by descriptions from Cambrian panarthropods of neural structures that contribute to understanding early evolution of nervous systems and resolving controversies about segmental homologies [ 4–12 ]. However, the rarity of fossilized CNSs, even when exoskeletons and appendages show high levels of integrity, brought into question data reproducibility because all but one of the aforementioned studies were based on single specimens [ 13 ]. Foremost among objections is the lack of taphonomic explanation for exceptional preservation of a tissue that some see as too prone to decay to be fossilized. Here we describe newly discovered specimens of the Chengjiang euarthropod Fuxianhuia protensa with fossilized brains revealing matching profiles, allowing rigorous testing of the reproducibility of cerebral structures. Their geochemical analyses provide crucial insights of taphonomic pathways for brain preservation, ranging from uniform carbon compressions to complete pyritization, revealing that neural tissue was initially preserved as carbonaceous film and subsequently pyritized. This mode of preservation is consistent with the taphonomic pathways of gross anatomy, indicating that no special mode is required for fossilization of labile neural tissue.
Birds have an enormously long evolutionary history: The earliest of them, the famed Archaeopteryx, lived 150 million years ago in what is today southern Germany. However, whether these early birds were capable of flying -- and if so, how well -- has remained shrouded in scientific controversy. A new discovery published in the journal Scientific Reports documents the intricate arrangement of the muscles and ligaments that controlled the main feathers of the wing of an ancient bird, supporting the notion that at least some of the most ancient birds performed aerodynamic feats in a fashion similar to those of many living birds.
An international team of Spanish paleontologists and NHM's Director of the Dinosaur Institute, Dr. Luis M. Chiappe, studied the exceptionally preserved wing of a 125-million-year-old bird from central Spain. Beyond the bones preserved in the fossil, the tiny wing of this ancient bird reveals details of a complex network of muscles that in modern birds controls the fine adjustments of the wing's main feathers, allowing birds to master the sky.
"The anatomical match between the muscle network preserved in the fossil and those that characterize the wings of living birds strongly indicates that some of the earliest birds were capable of aerodynamic prowess like many present-day birds," said Chiappe, the investigation's senior scientist.
Researchers studying organic material from dinosaur bones have been able to show that the organic material in the samples contained original soft tissue material from Mesozoic dinosaurs. The x-ray techniques at the ALS were key to showing a possible mechanism for this unexpected preservation—iron nanoparticles associated with dinosaur blood vessels were identified at the ALS. Researchers hypothesized that the iron had come from dinosaurs’ blood and muscle cells during decay, and were able to identify iron-facilitated reactions that contribute to preservation. If these reactions occur in other organisms that end in the fossil record, similar preservation may allow the identification of molecular evolutionary relationships, rates and direction of evolutionary change, and eventually the characterization of other traits that have, until now, remained beyond scientists’ grasp.
