Frozen in Time: Prehistoric Life in Antarctica
Language: English
Pages: 248
ISBN: 0643096353
Format: PDF / Kindle (mobi) / ePub
No other continent on Earth has undergone such radical environmental changes as Antarctica. In its transition from rich biodiversity to the barren, cold land of blizzards we see today, Antarctica provides a dramatic case study of how subtle changes in continental positioning can affect living communities, and how rapidly catastrophic changes can come about.
Frozen in Time presents a comprehensive overview of the fossil record of Antarctica framed within its changing environmental settings, providing a window into a past time and environment on the continent. It reconstructs Antarctica’s evolving animal and plant communities as accurately as the fossil record permits.
The story of how fossils were first discovered in Antarctica is a triumph of human endeavor. It continues today with modern expeditions going out to remote sites every year to fill in more of the missing parts of the continent’s great jigsaw of life.
KEY FEATURES
* Copiously illustrated with magnificent color images
* Provides an overview of the discovery and exploration of Antarctica
* Gives a clear guide to the palaeontology of Antarctica
* Includes contemporary issues of heritage and preservation
* Outlines the possible major impacts of climate change
geological, unweathered form. And although only a small percentage of the Antarctic continent is exposed above the ice sheet, its geology is now reasonably well known. The oldest rocks found on Antarctica are of Precambrian age – more than 540 million years old. These form basement rocks that once were areas of ancient continental crust called ‘cratons’. There are thick sedimentary sequences of both Archaean and 41 Frozen in time Neogene mya Cenozoic Era Pleistocene 1.8 Pliocene Age of
pterosaurs called the rhamphorhynchoids. The Antarctic pterosaur was small-to-medium-sized and probably had a wingspan of about one to two metres. In any event, Cryolophosaurus was the king carnivore at the top of the food chain in this environment, and this exciting find in the highest elevation of Antarctica marks the beginning of big meat-eaters as a dominant predator of the Mesozoic Era. However, Jurassic fossils had been recognised in Antarctic sequences much earlier spanning the spectrum of
ancient life – from plants found at Hope Bay to four beetle wing cases collected by WN Croft of the British Museum (Natural History) in 1946. 8 A lacustrine ray-finned fish collected during the 1960s by David Elliot from the interbedded sediments in the Mt Kirkpatrick basalt was named Oreochina ellioti. Many different sorts of macroinvertebrates from the Early to Late Jurassic are also known from marine deposits. In late 2003, Bill Hammer and his team collected the remains of a sauropod,
margin from as far back as 1.9 billion years ago until around 560 million years ago. Most of the other known continental fragments (including the ancient Baltic regions ‘Baltica’, Siberia, northern China, southern China and ‘Tarim’) were in close proximity to this landmass, so they formed the first supercontinent, named Rodinia after the Russian ‘rodit’ meaning to beget or grow. 2 The palaeomagnetic record of the rocks is useful here as Earth’s magnetic field will align minute magnetic particles
was forested with southern beeches, Nothofagus 146 A flowering plant leaf from the Eocene. Photo: David Cantrill. spp., now well known in the earlier Gondwana continents, plus many other groups now known in southern hemisphere cold temperate rainforests such as in Tasmania, New Zealand and South America. One surprise was the presence of pine pollen known under the name Dilwynites, now known to belong to the ancestors of the Wollemi Pine, Wollemia nobilis. The discovery of this evidence of past