Let’s mix up some ‘Cenozoic’ for a little adventure. Making fossils is not only fun but also a creative way for kids to learn about paleontology. A dash of plaster, paper cups and various objects, paints and colour pens does the trick. I find students have a particular fascination with fossils and exploring Earth’s species that have been and gone. In keeping with the Earth and Space science curriculum, there is a teaching unit related to dating geological events. From radiometric dating, fossils, erosion, tree rings and even volcanic events, various scientific methods and philosophies can be explored to stimulate thought and research.
Portrait of our Planet
The cover story this month in the New Scientist Magazine outlines a beautiful article on evolution and the future of species – 7 billion years from now. Some may regard it as being alarmist – but at the very least it makes you reflect on the future of our planet. What will Earth’s final chapters of life illustrate? Planet Earth is approximately 4.6 billion years old and the evolution of life has come a long way in that time. But what will the future behold – it’s quite hard to imagine? Will life revert to the beginnings of when Earth first formed, with species diminishing in numbers and size? How will species adapt, migrate and evolve? An educated guess can only but hypothesise bizarre life forms that may emerge. James Lovelock, best known for his Gaia hypothesis is convincing in his argument that it is the biosphere that greatly affects the chemistry of the Earth’s surface, including oceans and the atmosphere. The Metaphor of Gaia has been an inspiration for scientific enquiry, given the complexity to prove the hypothesis with current scientific methodologies. But Earth’s processes are also in the game as plate tectonics transform the geosphere and consequentially the biosphere’s fate.
And what is the fate of human life? The fossil record does not inspire the greatest confidence in the future of mankind. Mammal species survive approximately one million years on average. So far, humans have existed for 200,000 years. How will we survive threats from disease, climate change, ecological degradation and natural disasters? Is it a matter of Homo sapiens evolving into a new species to fit a completely different environment on Earth – or life on another planet?
Messel Pit Fossil Site, Germany
Although not unique specifically to New Zealand, I do have fond memories of seeing a quick glimpse of the Messel Pit Fossil Site, located not far from Frankfurt in Germany. A UNESCO world heritage site since 1995, I was keen to have a look. Unfortunately I didn’t have the time to see the fossil site in the caldera of once a volcanic lake. I was still lucky to see the museum at least, which displayed fossils from the Eocene era, 47-50 million years old that had been preserved in an anaerobic environment. Shale and resin remains are rich and the Messel Fossil site is claimed to be one of the most diverse fossil sites in the world.
So what was life like around 47 million years ago? Floral diversity was rich. Green and golden algae were abundant along with diatoms and dinoflagellates. Coniferous and fern remains are rare but what is a treasure trove is the large numbers of flowering plant remains, with leaves, seeds, fruits and flowers clearly seen. So far, 96 families of angiosperms have been identified, of which 15 are monocotyledons and 81 dicotyledons. The vegetation was indicative of a lush tropical region, continental plate movement has steered this region further from the equator since.
Insects have also been recorded and fossiled with accuracy – so detailed and artistic. Most of the insects identified were land dwellers, of which 60% were beetles. Bees, wasps and ants were also abundant but their fossils more rare. Cicadas are quite diverse with relatively large wingspans. A number of fish species have been discovered and are sometimes referred to as ‘living fossils’, with enamel-covered scales and a snout similar to a crocodile. Amphibians were fascinating, with a number of frogs, snakes, lizards, turtles and crocodiles preserved beautifully. These species were at their peak of their diversity 250 – 65 million years ago. Snakes make up the majority of the reptile finds, although fossils of venomous snakes have not been found to date. Birds are the most common land vertebrates at Messel Pit; over 50 bird species have been identified and generally thought to be tree dwelling. Most of the bird fossils were in an excellent state of preservation with even colour patterns preserved. Birds of paradise, crows, finches, hummingbirds, flamingos and parrot ancestors have all been recorded.
Without a doubt, it is the mammals that have stolen the stage at Messel Pit. This was the age of the mammals, with the extinction of the dinosaurs around 65 million years ago. Skeletons, hair, wing membranes and intestinal contents have all been found. 45 species of marsupials, insectivores, bats, primates, edentates, rodents, carnivores and odd/even-toed ungulates have all been revealed. Anteaters were abundant, but it was the bats that were by far the most commonly found mammal specimens. Over 700 fossil specimens are related to seven species, with sophiscated wing structures and sensory systems. Marsupials no longer existed in Europe, yet early traces of possum like species have been discovered. Hoofed mammals were found, including the rhinoceros and tapirs, but it was the horses that maintained the most prevalent collection of fossils (at least 61 complete horse skeletons).
For the future …
The Earth supports an incredible amount of biodiversity of life. Acknowledging Earth’s history provides potential insight for how life will evolve next, and more importantly the implications of environmental degradation and climate change. It’s fascinating to relive history and even more intriguing to inspire the imagination of students to create their own species. The creation of fossils may just fantasise the minds of young evolutionary scientists and what may happen next.