Fossils for Africa - the sixth title in the Indigenous Knowledge Library series
Prof. Chinsamy-Turan's Fossils for Africa takes readers on an exciting, information-packed journey through the millennia to reveal life's greatest triumphs, adaptations and catastrophes.
Right here in Africa we have evidence of the earliest traces of life dating to about 3.8 billion years, when life on Earth was still single-celled and microbial. From these humble beginnings Africa’s fossil record shows how life became increasingly complex and diversified into a wide array of forms.
Fossils for Africa explores Africa’s incredibly rich fossil heritage and shows the importance of these fossils in unraveling the history of life on Earth. Dedicated chapters focus on the evolution of plants, insects, and the radiation of reptiles and mammals. The book draws to a close with the five mass extinction events that rocked Earth’s biodiversity in the past and ponders the current crisis facing our planet’s biodiversity.
The accessible text is brought vividly to life with illustrations by Luis Rey, photographs from leading palaentologists and clear scientific illustrations by Wendy Morison.
Title information: Fossils for Africa 9781107610057
Price and ordering information: click here
Title: Fossils for Africa
Author: Anusuya Chinsamy-Turan
Series: Indigenous Knowledge Library
Publisher: Cambridge University Press October 2014
Extent: 96 pages
Format: Paperback (full-colour).
Includes ten lavishly illustrated chapters, a glossary and an index, as well as activities, information boxes and pronunciation guides.
Chapter 1 Beginnings – what fossils are and what can be learnt from the fossil record
We live on the third planet in a solar system, on the outer edges of a spiral galaxy that is one of millions of galaxies in our universe. In its early days, about 4.5 billion years ago, Earth was very different to what we know today. There was no life in the oceans and no oxygen in the atmosphere. Much of Earth’s surface was liquid rock because of the activity of extreme volcanoes. These were turbulent times. Meteorites, as well as lightning and radiation from the sun, bombarded our planet. Geologists have very few clues about these early times because, over this immense time, rocks have weathered away and there are only a few places where Earth’s first rocks remain.
Chapter 2 From simple to complex life – what is known about the earliest life forms, and how they became more complex
Over the first two billion years of Earth’s history, bacteria and bacteria alone ruled the world. Initially they existed as single cells, but later single cells clustered together to form bacterial colonies. Bacterial colonies are evident in the fossil record as stromatolites, which are finely layered dome structures produced by bacteria capable of photosynthesis. In Africa, rocks from South Africa and Swaziland that date to 2.5 billion years preserve evidence of stromatolites.
Chapter 3 Earth becomes green – the evolution and radiation of plants
Almost 86% of the history of life on Earth was played out in water. During all this time, there were no living organisms on the land surface apart from cyanobacteria and stromatolites. In aquatic environments, red and green algae were abundant from about a million years ago. As they were living in water, except during the occasional drought, they had no problem with drying out. In addition, because they were able to float in water, algae did not need any specialised structural features to support them. However, on land the possibility of drying up was always present and organisms needed support to grow upright. Studies of plants and algae show that green algae called charophytes are the closest relatives of plants.
Chapter 4 The earliest land animals – the move of arthropods from water environments to land environments
The movement of life from water to land probably ranks as one of the most significant events in Earth’s history. Plants made the move to terrestrial environments about 473–483 mya, and the fossil record suggests that animals with jointed feet, the arthropods, followed soon after that.
Chapter 5 The radiation of animals with backbones – the diversification of animals with an internal bony skeleton and their movement onto land
Animals with a backbone (or spinal column) made up of a series of vertebrae that protect the spinal cord are known as vertebrates. They include fishes, frogs, reptiles, birds and mammals. Ancestral relatives of vertebrates are found in the 505-million-year-old Burgess Shale deposits, while the earliest known vertebrate is from China and dates to about 525 mya. By about 500 mya, remains of the jawless fishes, the Agnatha, are occasionally found in the fossil record.
Chapter 6 The rise of the reptiles – evolution of the first reptiles and their diversification
When amphibians made the transition to land environments, they were highly successful. However, when the first reptiles evolved, they out-competed amphibians and dominated the terrestrial landscapes. The reptile radiation is highly significant as they are the ancestors of all reptiles, as well as birds and mammals (see diversity chart on the next page). Reptiles were able to live successfully on land because they were able to live totally independent of water. Unlike amphibians, they laid their eggs on land.
Chapter 7 Enter the dinosaurs – the diversity of dinosaurs
Dinosaurs are the most famous prehistoric animals! Just about everyone knows about dinosaurs, and almost everyone has a favourite dinosaur. Dinosaurs were found at all latitudes and on all continents, even on Antarctica, and well within the Arctic Circle. There were many different kinds of dinosaurs: some were as small as a medium-sized turkey, whilst others were enormous giants about 20 times the size of a modern 5-ton elephant; some sported extravagant bony frills, plates and spines on their heads, bodies and tails; some developed wings, and yet others developed wings on their forelimbs and hindlimbs!
Chapter 8 From mammal-like reptiles to mammals – the diversity of mammal-like reptiles and the emergence of mammals
During the Middle to Late Permian period (about 270 mya), the ‘mammal-like reptiles’ or therapsids (the-RAP-sids) were the dominant vertebrates on land. They were synapsid reptiles (i.e. they had one pair of openings in their skulls – see page 49). The earliest of these synapsids are the sail-reptiles, the pelycosaurs, which are best known from North America, although there are some finds from Europe, but very few of them have been found in Africa. The therapsids arose from among the pelycosaurs. The diversification of the therapsids is particularly significant since among them are our mammalian ancestors.
Chapter 9 Mammals diversify – the radiation of mammals (including humans)
Dinosaurs and mammals co-existed during most of the 160 million years that dinosaurs dominated land environments in the Mesozoic period. During this time, mammals stayed small (no bigger than a house cat), unlike dinosaurs that diversifi ed into a wide range of shapes and sizes. Being small was probably a good survival tactic, and from the large size of their eye sockets, we suspect that they were also nocturnal (active at night). In these ways, mammals avoided any interaction with dinosaurs. However, it is worth noting that mammals also took advantage of opportunities as they arose: a few years ago, a rare find was made in China of a fossilised skeleton of a mammal with the remains of a baby dinosaur in its belly region!
Chapter 10 The ‘big five’ extinctions – the ‘big five’ extinctions that have dramatically impacted life on Earth through its 3.8 billion-year history
The previous chapters have highlighted the significance of the fossil record in assessing prehistoric life. They have shown how and when different forms originated and diversified. By now it should be quite apparent that life on Earth changed over time and that many life forms became extinct. Palaeontologists generally accept that there are background ‘normal’ extinctions that occur among life. Usually species live for about 5–10 million years, and extinctions happen at a rate of about one every 200 years. This background extinction rate usually corresponds to the origin of new species. When there is an imbalance in terms of the number of species that go extinct and the number of new species that originate, an extinction event is identified. A mass extinction occurs when over 75% of species go extinct within a short span of time (in geological time scales this equates to roughly within 2 million years).
About the Author
Professor Anusuya Chinsamy-Turan is a palaeobiologist and is Head of the Department of Biological Sciences at the University of Cape Town. She is a global expert on the microscopic structure of the bones of extinct and extant vertebrates. Her work has been recognised by several highly acclaimed awards. In 2005 she won the ‘South African Woman of the Year Award’, which acknowledges her contribution to science both in terms of research and science communication to the wider public. In the same year she won the ‘Distinguished Women Scientist Award’ from South Africa’s Department of Science and Technology. She has published extensively in scientific journals, as well as in the popular press. She has also published two academic books and a children’s book on African dinosaurs. In 2013 she was awarded the ‘The World Academy of Science (TWAS) Sub-Saharan Prize for the Public Understanding and Popularization of Science’.
About the Indigenous Knowledge Library series
Cambridge’s Indigenous Knowledge Library series offers a wealth of readily available, exciting and accessible material as a resource for high school learners and teachers for researching this invaluable aspect of our heritage. Written by authorities in their fields, the series reveals the relevance and richness of African indigenous knowledge across a range of topics.
The books are filled with full-colour illustrations, information boxes and activities. Helpful extras include a glossary, an index and a list of resources that will simplify the process of discovery and enhance the enjoyment of learners and teachers as they delve into their African past.
Other titles in the Indigenous Knowledge Library:
- Astronomy of Timbuktu - Thebe Medupe
- Great South African inventions - Mike Bruton
- Indigenous mining and metallurgy in Africa - Shadreck Chirikure
- Traditionally useful plants of Africa - Phakamani m'Afrika Xaba and Peter Croeser
- The archaeological heritage of Africa - Gilbert Pwiti and Webber Ndoro