Australia’s Polar Cretaceous mammals

Dr Thomas H Rich (Australia) The Cenozoic Era is commonly referred to as the ‘Age of Mammals’. That is certainly the time in the history of life when their fossils are most abundant and diverse. However, two-thirds of mammalian history was during the Mesozoic Era – and they appeared about the same time as the dinosaurs. All continents except Antarctica have some record of the early, Mesozoic mammals. Of those that do, Australia has the most meagre record of all. Despite this, with this landmass that today has the most distinctive terrestrial mammals on the planet, their Mesozoic origins are so enigmatic that it has motivated a major effort since 1984 to search for fossils of those mammals that lived alongside the dinosaurs on this now isolated continent. Fig. 1. A map of Australia showing the location of the four sites where Cretaceous mammals have been found on the continent. During the Cretaceous, Australia was much further south than at present. Shown here are the lines of latitude at that time on the continent: 50o south, 60o south and 70o south. The famous Lightning Ridge opal field has provided some of the answers – two different early Late Cretaceous egg-laying mammals (the monotremes), as well as a third mammal that may be a monotreme, have been discovered there. One thousand, three hundred kilometres to the south-southwest along shore platforms pounded by the waves of the Southern Ocean, which expose those rocks on south coast of the continent, are three sites … Read More

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Highlights from the Museum am Löwentor in Germany

Jack Wilkin (UK) The Museum am Löwentor in Stuttgart, Baden-Württemberg, is one of the world’s greatest depositories of fossils. The museum was founded in 1985 and, since then, it has built up a vast collection of over 4.1 million fossils and has a 3,500m2 exhibition space, spilt over two levels. It is organised in chronological order. As you progress through the building, you can trace the evolution of life on Earth from the first cells all the way to the present, telling a more-or-less complete story of Germany’s geological history. This brief article will focus on just a few of the highlights at the museum. The amber collection The museum houses roughly 30,000 amber specimens from around the world, including samples from the Dominican Republic, the Baltics and the Lebanon, to name just a few places. The highlights of the collection include the largest piece of amber in the world from the Miocene of Borneo, as well as the world’s biggest damselfly and dragonfly inclusions. Triassic vertebrates There is an extensive collection of Triassic vertebrates from Baden-Württemberg, including, not just complete skeletal reconstructions, but also realistic life models. Fig. 1. Exhibits at the museum.One group that is featured in the exhibit were the placodonts – an enigmatic group of marine reptiles that superficially resemble turtles, although the two groups are unrelated. Many species, such as Placodus gigas, had large, flat teeth designed for crushing shells. The apex land predator of Central Europe at the time was the 5.6m, Batrachotomus. It … Read More

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Other mass extinctions

Neal Monks (UK) The extinctions at the Cretaceous-Tertiary (K/T) boundary make up what is probably the most famous geological event in popular culture. This is the point when the great reptiles that characterise the Mesozoic went extinct. Alongside the dinosaurs, the giant marine reptiles died out too, as did the pterosaurs, and a whole host of marine invertebrates, including the ammonites and belemnites. What happened? Some geologists argue the climate changed over a period of a million years or more, thanks to the massive volcanism that created the Deccan Traps in India. Others maintain that the K/T extinctions happened suddenly, pointing to evidence of a collision between the Earth and an asteroid. Perhaps there wasn’t a single cause, but rather a variety of factors: volcanism, climate change, asteroid impact, underlying changes in flora and fauna, and perhaps even variation in the output of the Sun and resulting weather patterns. That life on Earth can be wiped out this way is the stuff of disaster movies as much as TV documentaries. However, what comes as a surprise to many people is that there wasn’t just one mass extinction at the K/T boundary, but a whole series of them that can be observed throughout the fossil record. One of them, the Permo-Triassic extinctions, appear to have been even more catastrophic than the K/T extinctions, and at least three other extinction events are comparable in scale. In between these five big extinctions were lots of smaller extinctions that aren’t well studied, but had … Read More

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New museum in northern Greece: The Siatista Historical Paleontological Collection, the first record of a stegodon in Europe and the making of the straight-tusked elephant

Dick Mol (The Netherlands), Evangelia Tsoukala (Greece), Evangelos Vlachos (Greece), Anna Batsi (Greece), Hans Wildschut (The Netherlands), Dimitra Labretsa (Greece) and Wilrie van Logchem (The Netherlands) The Historical Palaeontological Collection of Siatista (HPCS), housed in a school building in Siatista, Kozani, Macedonia in Greece, was studied by the authors during the summer of 2009. The collection was assembled by local people from 1902 onwards, under the initiative of Nikolaos Diamantopoulos. Anastasios Danas, a high school teacher at the Trampantzeion Gymnasium in Siatista, was the main collector and he founded the Siatista’s palaeontological collection in 1906. The recovered records of the collection are minimal and it is not always clear from which locality the fossils were collected. However, the archived documents indicate that all the fossils were collected in the larger region of Siatista. Fig. 1. Replica of the Pleistocene straight-tusked elephant, Elephas antiquus, the eyecatcher of the Siatista Museum In 1972, Prof Ioannis Melentis, famous for his studies and publications on the fossil proboscideans of Greece, realised the importance of the collection and, in 1980, he became involved in the study and management of the collection, which was officially donated to the community of Siatista in 1994. The first exhibition was held in the Trampantzeion in 1982. In 2011, the collection was put on display in this beautiful building in Siatista, which was built in 1888. In a short time, it became one of the attractions of Siatista, telling the story of the large pachyderms that once roamed the northern … Read More

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Fossil of hairy, squirrel-sized creature sheds light on evolution of earliest mammals

Kevin Jiany (USA) It appears that a 165myr-old omnivore may have had an armadillo-like gait. A newly discovered fossil has revealed the evolutionary adaptations of a 165myr-old proto-mammal, providing evidence that traits such as hair and fur originated well before the rise of the first true mammals. University of Chicago scientists have described the biological features of this ancient mammalian relative, named Megaconus mammaliaformis, in the August 2013 issue of Nature. As Zhe-Xi Luo, professor of organismal biology and anatomy told me We finally have a glimpse of what may be the ancestral condition of all mammals, by looking at what is preserved in Megaconus. It allows us to piece together poorly understood details of the critical transition of modern mammals from pre-mammalian ancestors,” . Fig. 1. A new Jurassic fossil, Megaconus mammaliaformis, was recovered in the Inner Mongolia region of China, at the famous Daohugou fossil site in the Tiaojishan Formation, which is dated to be 165myrs old. The site is northeast of Beijing. Megaconus comes from a group of primitive mammal relatives, predating modern mammal ancestors. Luo shared the details of this discovery with me during the summer of 2103 at a meeting in his third-floor office in the Anatomy Building on the UChicago campus. Discovered in Inner Mongolia, China, Megaconus is one of the best-preserved fossils of the mammaliaform groups, which are long-extinct relatives of modern mammals. Dated to be about 165myrs-old, Megaconus co-existed with feathered dinosaurs in the Jurassic, nearly 100myrs before Tyrannosaurus rex roamed the … Read More

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Hunting the Dutch beach of Hoek van Holland for fossils

Bram Langeveld (The Netherlands) Holland is a small country that lies for the most part below sea level, which can be quite problematical. However, if you are a fossil collector hunting for the fossils of animals from the Weichselian (Last Ice Age) and early Holocene, it is not such a bad thing. That is because the Dutch government regularly has sand deposited on Dutch beaches, which is dredged up from the bottom of the North Sea to fight erosion of the beaches by the sea. Taking this one step further, Holland also has large scale land reclamation projects, where whole new parts of Holland are made by spraying sand from the bottom of the North Sea onto a location close to shore until it rises above sea level. Fig. 1. Map of The Netherlands showing Hoek van Holland. Much of this sand is dredged up by big, specially equipped vessels, called trailing suction hopper dredgers, from a location known as ‘Eurogeul’, which is the route for big vessels to reach the port of Rotterdam. Here, the sea is approximately 13m deep, but is deepened to 30m, by removing sand from the bottom. Much of this sand is used to reinforce beaches and for land reclamation projects. However, it is not just sand that is dredged up … Fig. 2. Simple timescale of the late Pleistocene and Holocene.The North Sea Plain If we could travel back in time – approximately 30,000 to 100,000 years ago – we would find ourselves in … Read More

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