Imran Rahman, Author at PALAEONTOLOGY[online]

Apr12019

Patterns in Palaeontology: The Real Jurassic Park

by Jack Wilkin*1 Introduction: The Morrison Formation is renowned worldwide as one of the world’s most significant locations for dinosaur fossils. It covers more than 150 million square kilometres, running from Alberta in Canada to New Mexico in the United States, and from Idaho across to Nebraska (Fig. 1). The Morrison dates to the Oxfordian stage of the late Jurassic period, some 155 million to 148 million years ago. It is what is known as a Konzentrat-Lagerstätten, meaning that it has a very high concentration of fossil remains, with extensive bone beds created by flash floods depositing lots of bones in one place. The Morrison provides palaeontologists with remarkable insight into a late Jurassic terrestrial ecosystem. Not only does the formation contain some of the largest din...

Jan12019

Fossil Focus: Diploporitans

Fossil Focus

by Sarah L. Sheffield*1 Introduction: Echinoderms, a group of marine animals that includes familiar organisms such as sea stars and sea urchins, were much more diverse in the past than they are today. There are five living classes of echinoderms (sea stars, sea urchins, brittle stars, sea cucumbers and crinoids), but more than 20 extinct classes are known only from the fossil record. During the Palaeozoic Era (542 million to 251 million years ago), especially, echinoderms were incredibly diverse and thrived all over the globe (Fig. 1). This was a time of significant environmental change, with the climate ranging from very warm oceans with high sea levels and high atmospheric carbon dioxide concentrations to much colder oceans, with extensive glacial ice. By studying how fossil ...

Sep12018

Fossil Focus: Paracrinoids

Fossil Focus

by Maggie R. Limbeck*1 Introduction: The oceans of the Palaeozoic era (541 million to 252 million years ago) were full of animals that we are familiar with, such as fish, snails, and coral, but also included many organisms that look almost nothing like their living relatives. The further back in time we go, for instance to the Cambrian and Ordovician periods (541 million to 444 million years ago), the greater the difference in body plans, or morphologies, compared to modern species. Echinoderms are an excellent example of this — living members of the group, such as starfish and sea urchins, are easily recognizable, but many of their extinct, fossilized relatives from hundreds of millions of years ago look very different. Understanding these different body forms is important to palaeontol...

Aug12018

Patterns in Palaeontology: How do we measure biodiversity in the past?

Patterns in Palaeontology

by Emma Dunne*1 Introduction: Life on Earth is incredibly diverse. More than 1.7 million species have already been described and estimates suggest that there could be as many as 9 million in total. But exactly how this rich biodiversity has developed over the last 542 million years since the Cambrian remains the subject of debate amongst palaeontologists. Did biodiversity increase steadily from one geological period to the next, or did it wax and wane without any overall direction? These questions are crucial in a modern context: today, we are flooded with urgent reports on the state of biodiversity worldwide, with many scientists stating that we are in the middle of a biodiversity crisis driven by human impact, leading to what is being called the sixth mass extinction. To understand and...

Jul12018

Fossil Focus: Blastoids

Fossil Focus

by Jennifer E. Bauer*1 Introduction: The ancient seas of the Palaeozoic era (541 million to 252 million years ago) teemed with unusual creatures that would be almost unrecognizable to us today. Although these animals look very peculiar, they often have living relatives that we are more familiar with. Consider echinoderms, such as sea stars and sea urchins: these marine animals can be recognized easily by scientists and the general public alike due to their distinctive five-fold symmetry and often vibrant colours. However, the Palaeozoic fossil record of echinoderms includes a wide range of forms that are radically different from living species. Indeed, there are only 5 major living groups of echinoderms, but about 20 extinct groups known only from the Palaeozoic. This means that the foss...

May12018

Fossil Focus: Thalattosuchia

Fossil Focus

by Mark T. Young*1, Sven Sachs2 & Pascal Abel3 Introduction: To most people, crocodilians are large-bodied carnivores that have been unchanged since the age of the dinosaurs. However, during their 230 million-year history, modern crocodilians and their extinct relatives evolved a stunning diversity of body plans, with many looking very different from those alive today (crocodiles, alligators, caimans and gharials). The first crocodylomorphs (the term used for living crocs and various fossil groups) are known from the Late Triassic Period, approximately 235 million to 237 million years ago. These animals lived on land and looked much more like a greyhound than a crocodile, with long legs and a skull that was deep like that of a meat-eating dinosaur, rather than flattened like that ...

Oct12017

Patterns in Palaeontology: The development of trilobites

Patterns in Palaeontology

by Lukáš Laibl*1 Introduction: Trilobites are an iconic group of ancient animals, with a fossil record that dates back more than 500 million years and consists of some 17,000 species. These extinct arthropods are characterized by a hard, mineralized exoskeleton, which greatly enhances their chances of being preserved as fossils. The exoskeleton is thought to have been mineralised soon after they hatched from eggs, and so we can find various growth stages of trilobites in the fossil record, including individuals less than half a millimetre long. That makes it possible to study the entire post-embryonic development (that is, the development after they hatch from the egg) of numerous species. This is important because work on the development of ancient organisms provides data crucial for ou...

Sep12017

Education and Outreach: The history of dinosaur palaeoart

Education and Outreach

by Szymon Górnicki*1 Introduction: Non-avian dinosaurs are iconic animals that dominated life on land for 170 million years during the Mesozoic era, and have captured the imagination of scientists and non-scientists alike for as long as we have known about them. As a result, dinosaurs have also dominated palaeoart — artistic representations of past life. Palaeoart is closely linked to the science of palaeontology, resulting from the desire to reconstruct what extinct organisms looked like when they were alive, and is increasingly informed by the latest scientific discoveries. This article provides a brief historical account of dinosaur palaeoart, explaining how this work has changed as our understanding of the anatomy and biology of dinosaurs has improved. Scaled-up lizards: The first ...

Jun12017

Patterns in Palaeontology: Environments of the Cambrian explosion

Patterns in Palaeontology

by Thomas W. Hearing*1 Introduction: Shimmering curtains of sunlight stream down through the waters of a shallow sea that has been advancing landwards for several million years. This transgression has formed wide areas of shallow continental shelf seas. The sea bed teems with life — some of it familiar, some much less so. The oddities begin on the floor of this tropical sea: a reef built not of corals, but by carbonate-producing microbes and the strange archaeocyathan sponges, alongside creatures that look more conventionally sponge-like but probably aren’t. Streams of seaweed drift on the currents; closer examination reveals small, snail-like shelled molluscs on some of the tendrils. A trilobite scuttles for cover, startled by the flickering shadow passing overhead, and narrowly avoids ...

Apr12017

Patterns in Palaeontology: Palaeoproteomics

Patterns in Palaeontology

by Caitlin Colleary*1 Introduction: The fossil record is our only direct window to the history of life on Earth. The ability to find and study the remains of animals, plants and other organisms that lived millions of years ago is extraordinary, and as technology has improved over the past few decades, scientists have realized that fossils contain more information about the stories of extinct life forms than even Charles Darwin could have imagined. Biomolecules (such as DNA, proteins and lipids) that make up modern animals contain information about how their bodies work (physiology — that is, physical and chemical functions), relationships to other animals and their evolutionary histories. With the advances in analytical tools such as high-resolution mass spectroscopy, the study of biomol...