The History of Life on Earth
The table below tells you how life began and changed, from Earth's beginnings to the present. Geologists divide Earth's history into different periods, such as the Cretaceous, when T rex lived. The tables below and on the left give dates in millions of years - for example, the Jurassic began 200 million years ago (mya) and lasted until 145 mya. Below you can also see some of the main features and events which took place in each period - the first dinosaurs lived in the Triassic, 230 mya, and the first cat evolved in the Oligocene, 30 mya.

These periods are mainly defined by the kind of animals and plants which lived at these times. At the end of most periods there were mass extinctions. The most catastrophic of these was at the end of the Permian, when a huge number of species died out - 96% of invertebrates, 66% of vertebrates, and 50% of plants. At the end of the Cretaceous there was another major extinction event which killed off the dinosaurs and many other living things, such as ammonites.

The column on the right gives the dates of some of the animals and plants which appear in the Fossils and Bones workshop, either as fossils or as the skeletons which the children make. Species names are given in bold italics, e.g. Triceratops.

A NOTE ABOUT EVOLUTION
In the table you will se a lot of firsts - the first dinosaur, the first mammal, etc. But bear in mind that evolution is a very gradual process, and often there is no clear dividing line between an animal that is one type versus another. Scientists often argue about such things - for example, what exactly is a mammal, or a bird? There is a far smaller difference between say Archaeopteryx, the first bird, and the dinosaurs it evolved from, than there is between Archaeopteryx and a modern bird like a parrot or hawk. And the so-called first of a type of animal, such as the first whale, may look very little like a modern whale - it just has certain features (e.g. the shape of the skull) which tell us that all whales are descended from it.

HUMAN EVOLUTION
In the Miocene, around 6 mya, creatures evolved from apes which eventually developed into human beings. All the 'hominin' species we know of are given in the table, in the right hand column so they can be seen more clearly, with the dates they lived (e.g. Homo habilis, 2.2-1.6 million years ago), as well as the size of their brains (where known - given in cubic centimetres, or ccm). As you will see, brain sizes increase through time, with our own species, Homo sapiens, having the largest brains.
 
To see pictures showing life in each period, click on the name of each period, below or in the table to the left (COMING SOON).
There is a great deal of information in this table, so you may want to dip in and out!
 

Date

Period

Main features and events

Animals and plants featured in the workshop

4560-4000

Hadean

Earth forms from dust and gas around the sun.
Earth is bombarded by comets and asteroids and is a hot, lifeless place of molten rock.

4000-2500

Archaean

End of bombardment by asteroids. Continents of solid rock form, and then oceans. The atmosphere contains mainly nitrogen, methane and carbon dioxide. There is no oxygen.

About 3.8 billion years ago, life begins in the oceans: microscopic things called archaea, similar to bacteria. They do not need oxygen and live off energy stored in the rocks and minerals of the earth - chemicals such as sulphides. They are made up of just one cell- a very small sack of liquid, chemicals, little organs that produce energy, and DNA - the instructions for building the cell itself. It will be 3 billion years before living things have more than one cell (we have trillions in our own bodies).

2500- 542

Proterozoic

Cyanobacteria evolve - also known as blue-green algae. These are the first living things to photosynthesise, like plants. They take carbon dioxide from the air and water to make energy, and give off oxygen. Over the next few hundred million years the atmosphere fills with oxygen, and this allows new forms of life to evolve. Cells very slowly become more complex.

1850 - the first organism with cells containing a nucleus.

1500 - first complex cell, possibly a fungus.

1200 - first organisms on land.

713-635 - first evidence for multi-celled animals, possibly sponges.

565 - Ediacaran animals - found in Ediacara Hills in Australia and other countries. Include Charnia, a creature shaped like a feather, first found near Leicester, and other soft-bodied creatures similar to jellyfish and sea pens.

550 - first anthozoans (corals and sea anemones) and sponges.

542-

488

Cambrian

Enormous increase in animal diversity, known as the 'Cambrian explosion'. Many new types of marine animals evolve, many of which are still alive today.

540 - small shelly creatures.

535 - first trilobites (creatures like big woodlice, with bodies divided into three lobes), many other types of arthropods (creatures with bodies divided into segments, like modern insects and centipedes), first crustaceans (modern species include crabs, lobsters, shrimps), molluscs (like modern snails and squids), echinoderms (like modern starfish, crinoids, sea urchins), and many more types of animals.

530 - first chordates (fish-like creatures, with a cord along their backs which evolved into a backbone) - e.g. Pikaia - similar to a modern lancelet.

530 - first vertebrates - tiny fish with no jaws, e.g. Myllokunmingia and

Haikouichthys.

510 - first cephalopods (like modern nautilus, which looks like a squid in a spiral shell)

505 - creatures found in the famous Burgess Shale in Canada - strange looking animals like Marrella, Hallucigenia, Anomalocaris and Wiwaxia.

500 - first evidence of arthropods on land (fossils showing movements in the mud)

540 - Conocoryphe sulzeri - trilobite

488-

444

Ordovician

Huge increase in diversity of marine life - the number of species triples. Trilobites flourish.

485 - first vertebrates with bone - jawless fishes, e.g. Arandaspis (appeared 470). The first bony plates, scales, and possibly teeth develop.

480 - first starfish and crinoids

475 - first plants (spores of very simple plants)

450 - first burrows created by land animals (millipedes).

445 - mass extinction - half of all species die, mainly trilobites and echinoderms.

444-

416

Silurian

440 - First spores of complex plants

440 - new species of jawless fish

430 - first fish like sharks ('protosharks'), first fish with jaws

425 - first land plant, Cooksonia

420 - first arachnid (spider family), first land scorpion, first ray-finned fish

416-

359

Devonian

The 'Age of Fish' - huge increase in number of fish species. Also many new plant species, spreading across land and creating the first forests.

410 - first true fish teeth

400 - first horsetails (a plant which still exists today)

400 - first true sharks; first breathing of air (in lungfish)

395 - first lichen, first ammonoid (later evolved into ammonites)

385 - first tree-like plants, first big forests

380 - first spiders, first land millipedes and centipedes, first goniatites (an ammonoid)

380 - first lobe-finned fish. These later evolved legs and became amphibians

375 - first amphibian (modern species include frogs and newts), first coelocanth

365 - mass extinction - up to 70% of species die

360 - first ferns, first crabs

410 - Urasterella asperula - brittle star (thin legged starfish)

400 - Hapalocrinus elegans - crinoid, sea animal which attached to the sea floor and had a flower like structure for feeding.

359-

299

Carboniferous

Carboniferous means 'coal-bearing', and this was the period when huge forests grew over the earth and later turned to coal. Many kinds of plants flourished, including ferns, horsetails, and trees (which were not like modern trees).

350 - insects evolved wings - the first flying creatures

350 - the first large sharks

330 - the first amniote - Palaeothyris - a vertebrate which laid eggs. An important step in evolution, as the eggs can be laid on land, not only in water

325 - first dragonflies

320 - first conifers (trees like modern pines)

320 - giant millipedes, e.g. Arthropleura, up to 3m long!

310 - giant dragonflies (over 60cm wingspan)

310 - first plant-eating vertebrates; first synapsids - egg-laying animals like reptiles, e.g. Ophiacodon. These later evolved into mammals, and humans.

305 - first diapsids, a type of reptile, e.g. Spinoaequalis. Many animals evolved from diapsids including lizards, snakes, dinosaurs, croocodiles, and birds.

320 - Xyloiulus sigillariae - millipede

315 - Horsetails (also known as calamites, a plant).

Many of the fossils sold in the workshop are Carboniferous, as there are several local Carboniferous sites for collecting fossils, such as:

-Newhey Quarry, near Rochdale

-Poise Brook, Offerton

-Besom Hill, near Oldham

-Matlock Quarry

for details visit the ukfossils website

299-

251

Permian

Many kinds of reptiles developed in the Permian. The synapsids include Dimetrodon, a 3m long predator with a big 'sail' on its back. Some synapsids turned into mammal-like reptiles known as cynodonts, e.g. Procynosuchus.  They had features that helped them to hunt - their legs were longer and placed more directly under the body, they had different sorts of teeth like incisors and canines, and their eyes moved forward to help them see in 3D. In the Triassic the cynodonts evolved into mammals. However there were no dinosaurs yet - these did not evolve until the middle of the Triassic.

290-280 - seed plants and conifers diversify (that is, the number of species increased)

280 - Dimetrodon

280 - the first beetles

275 - ceratites (a type of ammonoid, later became ammonites)

275 - pelycosaurs die out (sail-backed reptiles like Dimetrodon and Edaphosaurus)

251 - largest mass extinction of all time - death of 50% of plant species, 96% of invertebrates (including all trilobites), and two thirds of amphibians, reptiles and therapsids (mammal-like reptiles). Caused by several things: huge volcanic eruptions which poisoned the air and starved the oceans of oxygen, global warming, and a huge lowering of sea levels which caused massive loss of animal habitats.

251-

200

Triassic

The Triassic, Jurassic and Cretaceous are known as the Mesozoic era, or the Age of Dinosaurs. Dinosaurs evolved from reptiles about 230 million years ago and died out at the end of the Cretaceous, 65 million years ago, lasting 165 million years in all. They are closely related to pterosaurs (the flying reptiles) and distantly related to crocodiles, but neither of these are dinosaurs - nor are the sea reptiles such as ichthyosaurs and plesiosaurs.

Once the climate disaster at the end of the Permian had settled down, a lot of new important animals evolved. These include:

245 - archosaurs - a large family of reptiles. They later evolved into crocodiles, dinosaurs and birds.

240 - goniatites die out (similar to ammonites)

Early Triassic - first ichthyosaurs, e.g. Mixosaurus (sea reptile resembling a dolphin) - grew to about 1m, although later ichthyosaurs were enormous - Shastasaurus grew to 21m, the largest sea reptile ever.

Euparkeria - a primitive archosaur, had some dinosaur-like features, such as long back legs, good for running fast, and a space in the skull in front of the eye which meant it had a good sense of smell.

Later Triassic - Postosuchus - a large archosaur, from a line which led to crocodiles, had a huge skull and teeth like T rex

Mastodonsaurus - the largest amphibian ever at 6m, looked like a crocodile

230-225 - first dinosaurs - Eoraptor, Herrerasaurus, Coelophysis - 1-3m long, they were slender and ran on two long legs, and had sharp teeth and claws and long necks. Dinosaurs first lived in Argentina in South America, but spread across the whole planet, diversifying into many species.

Late Triassic - Eudimorphodon -  one of the first pterosaurs, or flying reptiles. Pterosaurs had incredibly long fourth fingers which supported the wings, made of skin. They were about the size of a goose (10kg), but later pterosaurs grew enormous (Quetzalcoatlus had a 12m wingspan - as big as a small plane)

220 - the first turtle, Odontochelys

220 - first flies

220 - first prosauropods - a large plant-eating dinosaur, e.g. Plateosaurus, which grew to 10m in length and 700kg in weight. They had long necks and tails, and teeth adapted for chewing leaves, like the later sauropods (e.g. Brachiosaurus)

215 - Dicynodonts (see Permian period) evolved from mammal-like reptiles (e.g. Placerias, Lystrosaurus) into mammals - e.g. Morganucodon, Eozostrodon. They looked like shrews (or rats), with fur. They suckled their young with milk. All mammals evolved from these shrew-like creatures, including us.

Gingko - a tree which evolved in the Triassic and thrived during the Jurassic. It declined to just one species, alive today - Gingko biloba, or the maidenhair. It is used as a herbal remedy.

200-

145

Jurassic

The Jurassic was a time of huge monsters on land and sea, such as Allosaurus, Brachiosaurus, and Liopleurodon. It was also the time of the ammonites, a very successful group of sea creatures like squids in snail shells. Ammonites are very popular fossils which can be found on beaches all over Britain (see right).

195 - first ammonites and belemnites (a squid-like animal - the remains of belemnites are found in many places where ammonites are found; they look like teeth but are in fact the 'guard', a hard part of the squid's body on the inside.

195 - first sauropods - plant-eating dinosaurs with long necks and tails, which walked on four sturdy legs, e.g. Vulcanodon (7m long)

190 - first modern starfish

190 - first pliosaurs (marine reptiles)

190 - first lepidoptera - family which includes moths and butterflies - e.g. Archaeolepis

Early Jurassic - Mesolimulus - a type of horseshoe crab. Horseshoe crabs (not true crabs) first evolved in the Permian, but this species is very similar to the modern species, Limulus, which lives on the coast of North America, so it is thought of as a 'living fossil', like the Gingko tree.

First frog - Prosalirus

Ichthyosaurus - 2m long sea reptile resembling a dolphin, with a long thin snout full of sharp teeth for catching fish

Mammals continued to evolve, including Megazostrodon and Sinoconodon - still resembling rats or weasels

Middle Jurassic - Liopleurodon - the top predator in the seas of Europe, up to 10m long, with 1.5m jaws - a type of pliosaur, with a hefty body and huge flippers.

Plesiosaurus - a typical plesiosaur (sea reptile), up to 5m long with a very long thin neck, a small head, and four big flippers - a very fast and powerful swimmer.

Pterosaurs - several species of these flying reptiles evolved in the Jurassic, e.g. Dimorhpodon (1m long with big skull), Rhamphorhynchus (2m wingspan), and Pterodactylus (1m wingspan; many fossils have been found, in Germany). They caught fish with their long beaks.

Many species of dinosaur evolved, such as:

Dilophosaurus - a 6m long theropod - a predator which ran on two legs, with two small front legs, like T rex.

Megalosaurus - the first dinosaur ever discovered, in 1824 in Oxfordshire, a theropod.

Mamenchisaurus - a 26m sauropod which had the longest neck of any animal ever, up to 13m

Huayangosaurus - an early stegosaur, 4m long with two rows of plates along its back - possibly for defence, or for display

Late Jurassic

155 - the first bird, Archaeopteryx - 30cm in length (crow-sized), it had wings and a tail with long feathers, but unlike modern birds it had claws on its wings and teeth. It evolved from dinosaurs, and some palaeontologists think of modern birds as dinosaurs. There were many other small feathered dinosaurs which were similar to birds, known as maniraptors. Ten Archaeopteryx skeletons have been found; a copy of the most famous one is used in the Fossils and Bones workshop.

Many famous dinosaurs evolved in the late Jurassic, such as:

Allosaurus - a huge predator, 7-12m long, weighing up to 1.8 tonnes, which fed on large plant-eating dinosaurs

Sinraptor - a 9m theropod found in China

Compsognathus - a small theropod, only 1.3m long

Brachiosaurus - a 23m sauropod with huge legs and neck, weighing 30 tonnes. It could reach up 15m into the trees to eat leaves. Its humerus (upper arm bone) was up to 2m long.

Diplodocus - 25-30m long, another sauropod, one of the longest dinosaurs ever with an incredibly long neck and tail and a small head. It grabbed branches in its jaws and used its peg-like teeth to strip the leaves off. Its tail had up to 80 vertebrae.

Apatosaurus - once known as Brontosaurus, another sauropod, 23m long. Weighed as much as four elephants.

Camarasaurus - the most common sauropod in North America, 18m long.

Stegosaurus - 9m plant-eater which had two rows of diamond-shaped plates on its back, as well as four long and deadly spikes on its tail. There has been a lot of debate about the purpose of the plates - they may have been for defence, for controlling temperature, or for display. It ate plants on the ground, and had a very small brain.

Kentrosaurus - another stegosaur, 5m long, found in Africa

200 - ichthyosaur skull - found near Lyme Regis, on the 'Jurassic Coast'

200-145 - ammonites - the ammonites seen in the workshop are Jurassic. The slab with many small ammonites, which I found at Port Mulgrave in North Yorkshire, is about 190 million years old

190 - belemnites - Jurassic, found on North Yorkshire coast

155 - Archaeopteryx - bird

154-153 - Brachiosaurus

154-150 - Diplodocus

150 - homeosaurus - lizard

150 - Megalosaurus footprint

145 - Stenophlebia aequalis - dragonfly

144 - Pterodactylus antiquus - pterodactyl

140 - Mesolimulus walchi - horseshoe crab

Many of the fossils sold in the workshop are Jurassic, as there are a lot of Jurassic sites in Britain good for collecting fossils, such as:

-Port Mulgrave, Staithes and Kettleness, all near Whitby in North Yorkshire

-Watchet, Somerset

-the Dorset coast (known as the Jurassic Coast), near Lyme Regis

for details visit the ukfossils website

145-

  65

Cretaceous

The Cretaceous was a very long period (80 million years) in which many important and well-known animals and plants evolved, such as Tyrannosaurus rex and Triceratops. It ended 65 million years ago when a 10km asteroid crashed into the Yucatan Peninsula in Mexico, creating a 240km crater. This massive impact caused tsunamis, earthquakes, widespread fires, acid rain, and a cloud of dust which blocked out the sun causing a drop in temperatures. All of this led to the complete extinction of the dinosaurs and many other species, such as the pterosaurs, plesiosaurs, pliosaurs, and ammonites, and 60% of plant species. The KT extinction (as it is known) left huge gaps in ecosystems, allowing mammals to develop. Without the KT extinction human beings would not exist, and the world might still be ruled by dinosaurs.

Sequoias, currently the largest trees in the world (up to 110m high), first evolved in the Triassic and flourished in the Jurassic.

Bird evolution took off in the Cretaceous with many species, some similar to Archaeopteryx and others like modern birds. Many dinosaurs had feathers too; these did not first evolve for flight, but for warmth and to help movement, for example in gliding.

Early Cretaceous

Dinosaurs from the early Cretaceous include:

Psittacosaurus - 2m, like a fat lizard with a toothless beak

Iguanodon - 9m planteater with a vicous spike on its thumb, has been found in England

Muttaburrasaurus - 7m, like an Iguanodon but lived earlier, found in Australia

Gastonia - a 4m long ankylosaur, it had spines all over its back for defence, and a thick skull so it might have head-butted other members of the species.

Caudipteryx - 1m long, it looked a lot like a bird, with a beak, long thin legs, and feathers.

Microraptor - another small feathered dinosaur, related to Velociraptor, it probably couldn't fly but lived in trees gliding from branch to branch

Deinonychus - a famous predator which was the basis for the velociraptors in Jurassic Park (real velociraptors were much smaller). Another feathered dinosaur, it was 3m long and very quick and agile. It had a very long curved claw which may have been used to puncture the neck of its prey, to stop it breathing and kill it.

Ornithocheirus - a gigantic pterosaur, with a wingspan of up to 10m and a long jaw, it fed on dinosaurs.

Baryonyx - a 9m long theropod with a long head like that of a crocodile, adapted for catching fish. Similar to later Spinosaurus. Has been found in Britain.

Marsupials also evolved in the early Cretaceous, e.g. Sinodelphys. Placental mammals (in which babies grow in a womb) also evolved, e.g. Euomaia, from which humans may be descended. Mammals still looked like rodents, however, until the Paleocene (see below)

140 - first ceratopsian (horned) dinosaurs - ancestors of Triceratops

140-100 - diversity of stegosaurs and sauropods decreases, diversity of ankylosaurs (e.g. Gastonia) and birds (e.g. Iberomesornis) increases

125 - first flowering plants - the first flowers were tiny; flowers with large petals evolved 100-90 million years ago, e.g. Magnolia

100 - first bees - evolved to pollinate flowers

90 - ichthyosaurs die out

90 - first snakes

80 - first ants and termites

Late Cretaceous

The late Cretaceous was a period of many famous dinosaurs, such as:

Spinosaurus - possibly the largest theropod, 16m long, it had a sail on its back and a long snout like a crocodile. Plunged its jaws into water to catch fish. Seen in Jurassic Park III, fighting a T rex

Carcharodontosaurus - 11m African therapod with a huge skull - a terrifying predator, of which there were many in the Cretaceous.

Giganotosaurus - 12m predator similar to T rex, lived in Argentina and preyed on dinosaurs like Argentinosaurus.

Daspletosaurus - 9m long predecessor of T rex, lived in North America.

Albertosaurus - 9m tyrannosaur which lived in Canada

Tyrannosaurus rex - the most famous dinosaur of all. Up to 13m long, weighed 5-7 tonnes, lived at the end of the Cretaceous in North America. Probably both a scavenger and a hunter; evidence shows it preyed on Triceratops. Recent research has shown it had the strongest bite of any animal that ever lived, and could chew up a small car. It had up to 58 teeth which were banana shaped and of various sizes, up to 15cm (not including the root). Had tiny front arms but a huge neck to supprt the enormous head, and a long tail for balance. Had excellent vision and smell. A replica of one famous skeleton called Stan can be seen in the Manchester Museum.

Tarbosaurus - 12m Chinese relative of T rex with a less strongly-built skull.

Ornithomimus - 3m American therapod which looked a bit like an ostrich - had long thin legs, feathers and big eyes

Gallimimus - 6m theropod like a large version of an Ornithomimus. Lived in Mongolia. Long tail and slim legs mean it was a fast runner. It is not known what it ate.

Oviraptor - small feathered theropod, very like a bird, with a large squarish beak. Only one skeleton has been found, near to its nest of 15 eggs.

Velociraptor - small feathered theropod, 2m long. Had long claws, especially on its second toe, used for tearing flesh of prey. Lived in Mongolia. Much smaller than the velociraptors shown in Jurassic Park.

Troodon - 3m North American theropod, preyed on small lizards and mammals as well as baby dinosaurs. Fossils have been found of adults sitting on nests of up to 24 eggs.

Argentinosaurus - The largest land animal ever, a sauropod weighing up to 75 tonnes - ten times as much as a T rex. 30m long, lived in Argentina. It was so big that predators like Giganotosaurus could tear off chunks of its flesh and it would survive, healing so the predators could return for a second course.

Ankylosaurus - 6m North American plant-eater, well-protected by bony plates all over its back, and a large bony club at the end of a long tail. It could deal death blows with a swing of its tail.

Euoplocephalus - huge, 7m relative of Ankylosaurus, with a similar club tail to fend off predators.

Edmontosaurus - a very large (13m) duck-billed dinosaur, or hadrosaur. The 'duck-bill' was toothless and was used to crop large mouthfuls of vegetation. In its jaws however it had hundreds of small teeth ideal for grinding plants.

Parasaurolophus - a 9m North American hadrosaur, with a a long crest sticking out of the back of its head. The crest was hollow and may have been used to make deep, resonating calls.

Corythosaurus - another hadrosaur with a crest, but this one was a rounded plate shape on top of its head. It was probably used to make calls.

Triceratops - a very large plant-eater, 7m long and heavier (up to 12 tonnes) than the T rex which preyed on it. It had a remarkable skull - some were over 2m long, with two horns up to a metre long over the eyes, and a smaller one over the beak-like snout. As it grew older, holes developed in the huge frill behind the head. Frills show signs of injuries - from fights with other Triceratops, and from attacks by T rex - one even had a horn bitten off by a T rex.

Protoceratops - a ceratopsian (or horned dinosaur) like Triceratops, Protoceratops had a frill and a small nose horn but no large horns. It was also much smaller, 2m.

Styracosaurus - another ceratopsian, 5m long, with a remarkable array of six long spikes sticking up from its frill, as well as large holes in the frill to reduce its weight.

Pachycephalosaurus - a 5m North American plant-eater, it had a domed, very thick skull (its name means 'thick-headed lizard') with bumps on the snout and back of the skull.

Other animals from this period include:

Deinosuchus - a gigantic crocodile, up to 9 tonnes and 12m in length. Lived in North America at the same time as Daspletosaurus, but was more powerful. Probably hunted in the same way as modern crocodiles, lurking at the water's edge.

Pteranodon - North American pterosaur, 1.8m long with a wingspan up to 6m. It flew in flocks over water, hunting for fish. Fish bones have been found in the stomach of some fossils, and the long streamlined skull was ideal for diving into the water.

Quetzalcoatlus - the largest flying animal of all time, a pterosaur with a 12m wingspan. Weighed only 250kg because of air sacs inside its bones. Probably flew over land, hunting dinosaurs. Named after an Aztec god.

Mosasaurus - a huge, 15m long sea reptile with flippers and crocodile-like jaws. Its bite marks have been found on ammonites and large turtles.

Elasmosaurus - one of the last plesiosaurs (sea reptiles with flippers), 9m long. Over half its length was its neck, which had 71 vertebrae - more than any other animal that has ever lived.

Kronosaurus - another giant sea reptile, one of the last pliosaurs, 9m long with flippers and long jaws like a crocodile.

Hesperornis - a large, flightless sea bird from North America. It had tiny wings, big feet and a long, toothed bill. It could swim under water to catch fish.

Ichthyornis - a small (30cm) bird resembling a seagull that used its sharp, toothed beak to catch fish.

Nemegtbataar - a small (10cm) mammal similar to but not closely related to mice and rats.

112 - Sarcosuchus

81 - Pteranodon longiceps

75 - Oviraptor

65 - T rex,Triceratops

65-
55

Paleocene

After the extinction of the dinosaurs there was room for mammals to grow larger and diversify into many species. In the next 10 million years, a time known as the Paleocene, a huge number of mammals and birds evolved. This continued in the following periods.

60 - first primates (our own ancestors), first anteaters; first carnivorous mammals; first hedgehogs, shrews and moles

60 - many new flightless birds; first owls

55 - first grasses; many new species of flowering plants

55 - modern bird groups divesify - first song birds, parrots, divers, swifts, woodpeckers

55 - first whale (Himalayocetus); first rodents; first horses; first rabbits; first elephants

Some animals which lived in the Paleocene:

Titanoboa - an enormous, 13m long snake, the largest land predator of its time

Presbyornis - a 1m tall bird looking like a flamingo but with a wide bill - a distant relative of ducks and geese which lasted for 20 million years

Plesiadapis - a small (18cm) creature similar to a squirrel, but more related to primates

55-

34

Eocene

52 - first bats

50 - first brontotheres (large mammals); first rhinos; first camels; primates diversify

40 - modern moths and butterflies

35 - grassland ecosystems develop

35 - major extinction of reptiles and amphibians

35 - whales diversify; new mammal groups appear - glyptodons, ground sloths, dogs

35 - first hawks and eagles

Some animals which lived in the Eocene:

Anguilla - the first eel

Primapus - similar to a swift

Diatryma - a huge flightless bird, 2m tall, which stalked prey through forests. It was the largest predator of its time, larger than any mammal. It had a huge skull with a strong beak.

Uintatherium - a huge (3.8m) mammal like a rhino with six rounded horns on its head.

Andrewsarchus - at 3.7m, the largest predatory land mammal that has ever lived. It had a huge skull (over 1m) and looked like a hyena.

Hyaenodon - not a hyena but a large predatory mammal that looked like one

Hesperocyon - 80cm long North American mammal that looked like a raccoon, with a long tail and short legs, but was in fact the first member of the dog family, the Canidae. All dogs, wolves and foxes evolved from this creature.

Icaronycteris - one of the first bats, 14cm long.

Palaeolagus - one of the first rabbits, but very small - 10cm - and with shorter back legs.

Protorohippus - one of the first horses, although it was only 38cm high and had toes rather than hooves.

Mesohippus - a 60cm tall horse with three toes.

Darwinius - a small primate from the middle Eocene, a distant ancestor of humans

Eosimias - a tiny (5cm) primate from China which looked like a marmoset

Ambulocetus - a 3m long ancestor of whales, which had legs and could walk as well as swim. Its skull and teeth tell us it was related to whales.

Moeritherium - an early member of the Proboscidae family, from which elephants and mammoths evolved. It looked like a hippo with a long snout.

55-45 - Lamna otodus, shark

50 - Archaephippus asper, a spadefish

50 - Propelodytes wagneri - frog

50 - midge in amber

34-

23

Oligocene

30 - first pigs, first cats (that is, the felidae family; modern pet cats are descended from the African wildcat from about 10,000 years ago); brontotheres die out

25 - first deer

Paraceratherium - a gigantic hornless rhinoceros, 8m long, 5.5m high, weighing 15 tonnes - the largest land mammal that ever lived. Fed on the tops of trees like giraffes.

Miohippus - a type of horse

Stenomylus - a 1.5m tall humpless camel from North America.

Eomys - a small, gliding rodent like a flying squirrel

23-

  5

Miocene

20 - first giraffes; birds diversify

15 - first mastodon (an elephant-like animal); first bovids (cow family); many types of very large animals in Australia

10 - savannahs and grasslands established, allowing many species of grazing mammals to flourish, as well as carnivores which feed on them; horses grow larger; small mammals and rodents diversify

10 - insects diversify, especially ants and termites

Species from the Miocene include:

Carcharodon megalodon - a gigantic, 18m long shark, weighing about 50 tonnes. The largest predatory shark that ever lived, its jaws were as tall as a man.

Argentavis - by far the largest flying bird ever, with a wingspan of 8m. Looked like a condor, and lived in Argentina. Probably a scavenger, it had a huge beak and claws to rip open carcasses.

Thylacosmilus - a large (1.5m) predatory marsupial with two enormous front fangs. Lived in South America.

Enaliarctos - 1.5m long North American ancestor of seals, it had flippers and swam in the sea but was active on land too.

Teleoceras - a large, 4m long rhinoceros from North America. It had one small horn on the tip of its nose. Hundreds of fossils have been found.

Merychippus - a 1.1m tall horse that lived on the new grasslands of the Miocene. A fast runner, it was the first equine to have just one hoofed middle toe on each foot. Modern horses are descended from Merychippus.

Pliohippus - a descendant of Merychippus, but not an ancestor of modern horses. Slightly smaller than a modern horse.

Deinotherium - a huge (4.5m tall) relative of mastodonts (similar to elephants). Its tusks curved down and back from the front of the lower jaw, and may have been used to hook branches to drag them down and reach the leaves. The trunk was much shorter than an elephant's. Weighed about 14 tonnes, more than a modern elephant.

Gomphotherium - like a small elephant (3m tall), with a long flat skull and four tusks - two long straight tusks on the upper jaw and two shovel-like tusks on the lower jaw. Mammoths evolved from these creatures in the Pliocene.

Proconsul - a possible ancestor of both monkeys and apes, 65cm long, lived in Africa. Like a monkey it was a lightly-built tree-dweller, and fed on fruits. Like an ape it had a large brain and no tail.

Sivapithecus - an ape related to orang-utans.

Dryopithecus - an ape the size of a monkey (60cm) but built like a chimp. Could walk on all fours like a chimp, but also swing in the trees.

28-1.5 Carcharodon megalodon

7 - Encope californicus - sand dollar

7-6 - first hominin - Sahelanthropus - brain size 360ccm  - an ape which may have walked on two legs, and may be an ancestor of humans. Found in Chad, Africa (all hominins up to 2 million years ago lived in Africa)

6.1-5.8 - Orrorin - may be the oldest known biped (walking in two legs), closely related to chimps as well as humans

5.8-5.2 - Ardipithecus kadabba - as with the previous two, it is not certain if this was a human or chimp ancestor

  5-

  1.8

Pliocene

Many hominin species evolved in the Pliocene (see right). About 2 million years ago the Australopithecines died out and the genus Homo evolved, beginning with Homo habilis. Many other fascinating and sometimes enormous animals also appeared in this period:

Castoroides - a giant ice-age beaver, 2.5m long. It had 15cm long front teeth, weighed up to 100kg and lived in North America.

Glyptodon - a 2.5m long relative of armadillos, with a rounded and well-protected body covered in tiles up to 2.5cm thick. Lived in South America.

Megatherium - a giant ground sloth, 6m long and weighing 4 tonnes. It was as big as an elephant and covered in long hair. It had long forelegs with enormous claws for gripping trees and fending off predators.

Equus - the genus which includes modern horses, zebras and donkeys.

Mammuthus - a successful genus of elephant-like creatures that survived throughout the Pliocene and Pleistocene; the last mammoths lived on Wrangel Island in the Arctic Ocean until 1700BC. The Steppe mammoth (600,000-370,000 years ago) was the largest, growing 5m tall with tusks up to 5m in length. The famous woolly mammoth weighed 8 tonnes and was covered in a thick layer of hair to keep it warm. The hair was similar in colour to that of humans - it could be brown, ginger or blond. Several frozen mammoths have been found in excellent condition. Scientists in Japan are trying to clone one to bring the mammoth back to life, like the dinosaurs in Jurassic Park. Mammoths may have been hunted to extinction by humans, who ate their meat and used the bones and tusks to make tools and works of art.

Coelodonta - an ice-age woolly rhinoceros, 3.7m long with a thick coat of shaggy hair. Had two long horns, probably used to shift snow when foraging. Died out at the end of the ice age, about 10,000 years ago.

Megaloceros - a large deer (2.7m long) with huge antlers even larger than those of a moose. Died out at the end of the last ice age.

Gigantopithecus - a huge ape, 3m tall, built like a gorilla but much bigger - weighed 540kg. Lived from 1 million to 300,000 years ago in Asia. Related to orang-utans.

HUMAN EVOLUTION

4.4-4 - Ardipithecus ramidus - a bipedal chimp-like ape, its skull was balanced over its spine (as in humans) and its toes were adapted for walking rather than grasping branches
4.2-3.9 - Australopithecus anamensis - another ape-like bipedal hominin from Eastern Africa
4.1-2 - Australopithecus afarensis - brain size 380-485ccm, height up to 1.5m. Thought to be an ancestor of humans; a very famous almost complete skeleton nicknamed 'Lucy' was found in 1974. Brain similar was size to a chimp's.
3.6-3 - Australopithecus bahrelghazali - found in Chad, known only from fragments of a jaw and teeth.
3.5-2 - Australopithecus africanus - brain size 428-625ccm, height 1.4m. Another ape-like bipedal human ancestor, with a small brain and human-like teeth. The first early hominin ever found (in 1924).
3.5-3.2 - Kenyanthropus platyops - lived alongside other hominins.
3-2 - Australopithecus garhi - brain size 450ccm - may or may not be one of our ancestors. Possibly the first hominin to use stone tools.
2.5 - Paranthropus aethiopicus - lived alongside early Homo species, so we are not descended from them. Had strong jaws for chewing tough seeds and vegetables.
2.5-1.2 - Paranthropus boisei - another ape-like hominin with even stronger teeth than Paranthropus aethiopicus.
2-1 - Paranthropus robustus - another species of Paranthropus, lived in southern Africa.

 
2.2-1.6 - Homo habilis - brain size 500-650ccm, height up to 1.3m; the first member of the genus Homo, to which we belong. The name means 'handyman', as stone tools have been found with fossils. Its brain was larger than the australopithecines whch came before, and its use of tools allowed it to access new foods, such as nuts, meat and bone marrow. Its teeth grew smaller as it needed them less for grinding tough vegetables.
2.4-1 - Homo rudolfensis - brain size 600-800ccm, height 1.6m. Closely related to Homo habilis but little is know about it.

 1.8-

10,000 years ago

Pleistocene

Aepyornis - a giant (3m tall) flightless bird like an ostrich. Nicknamed the 'elephant bird', it was the largest bird that ever lived, weighing 400kg. Its eggs were 34cm wide. Probably hunted to extinction by humans quite recently, when Europeans arrived in Madagascar.

Megalania - a giant monitor lizard, 8m long, like a huge Komodo dragon. Big enough to eat any of the large ice-age mammals of Australia. Had long, sharp teeth and weighed 1900kg.

Dinornis - a type of moa, a group of very large (3.6m tall) flightless birds from New Zealand. They were wiped out by the Maoris in the 16th century, as a result of hunting and habitat destruction.

Teratornis - a huge bird like  a condor but larger, with a 4m wingspan, whch lived in North America. Died out about 10,000 years ago when many of its prey also died out.

Arctodus - a giant bear, 3.4m long, weighing 900kg. A fast runner, with very powerful jaws. Lived in North America, and died out at the end of the last ice age, like many other large mammals.

Canis dirus - the dire wolf, similar to a modern grey wolf, but heavier - 80kg. Lived in North America, died out at the end of the last ice age, perhaps because of the spread of humans, wiping out the wolves' food sources.

Smilodon - a famous cat, known as a sabre-toothed tiger due to its two very long canine teeth, used for stabbing prey in the throat or belly then ripping it open. 2m long and about 400kg in weight, very strong and heavily built compared to modern big cats. Died out, perhaps because of competition from humans, at the end of the last ice age.

1 - Coral from Australia

30,000 years ago - Bison femur, rib and vertebra found on the Isle of Wight

HUMAN EVOLUTION

1.8-0.6 - Homo ergaster - brain size 600-910ccm, height up to 1.85m. A very important species, from which we are descended. Its name means 'workman', as its stone tool use was more complex than any hominin before. It was tall and slender, with a downward pointing nose - all adaptations for living on dry, hot savannahs. Probably the first species to migrate out of Africa, 1.8 million years ago, into Europe and Asia.

1.8-50,000 years ago - Homo erectus - brain size 750-1300, height up to 1.8m. Probably descended from Homo habilis, a very successful species that eventually lived alongside modern humans and may have hunted them. Looked similar to humans, although with a thick, heavy brow, large teeth and a less distinct chin. Much bigger brains than previous hominins. Either spread into Asia from Africa, or evolved in Asia and returned to Africa.

1.2-0.8 - Homo antecessor - brain size 1000ccm, height up to 1.8m. Lived in Europe (fossils have been found in Spain), but probably not an ancestor of modern humans.

0.6-0.2 - Homo heidelbergensis - brain size 1100-1400ccm, height up to 1.8m. The last common ancestor of both Homo sapiens (us) and Neanderthals. Tall, well-muscled, with heavy limb bones, suggesting tough physical activity like hunting. May have been able to speak. Found in Africa and Europe.

350,000-30,000 years ago - Homo neanderthalensis - brain size 1400ccm, height up to 1.7m. Neanderthals are a famous hominin, descended like us from Homo heidelbergensis. They lived at the same time as us but it is not known if the two species interacted. They were intelligent and buried their dead in graves. Unlike us they had low, sloping foreheads, very large noses and forward-projecting faces. They were physically strong and stocky, and well adapted to the cold environment of Europe. Hunted large and dangerous animals, like mammoths.
400,000-125,000 - archaic Homo sapiens - were similar to earlier hominins, having large faces, heavy brow ridges, thick bones and not much of a chin. Evolved into modern humans about 150,000 years ago.
150,000 years ago to present - Homo sapiens - brain size 1000-2000ccm, height up to 1.85m. More modern features of humans gradually evolved from about 250,000 to 125,000 years ago - a chin, smaller brow ridges, smaller faces, and higher, rounded braincases. Developed sophisticated tools, art, and jewellery: e.g. items discovered in a cave in south Africa from 73,000 years ago: pieces of red ochre engraved with geometric patterns, beads made of pierced shells, and finely made bone tools. Evolved in Africa and moved out about 60,000-40,000 years ago, ending up in Europe, Asia, in Australia about 45,000 years ago and in North America about 16,000 years ago. Beautiful cave paintings found in Europe date to as much as 30,000 years ago (the Chauvet caves in France).

10,000 years ago-present

Holocene

The Holocene is the period in which human beings developed agriculture (farming) in the near east, which led to settled communities and stone buildings (the earliest we know is Gobleki Tepe, in Turkey, a stone-carved temple from 12,000 years ago). The first cities and civilisations were in Sumer (Iraq) and Egypt.