- Microfossils
Figure 33.1 Precambrian planktonic foraminifera (protozoans).
- Stromatolites
Figure 33.2 Ordovician (ca. 500-425 Ma) agal heads (stromatolites) near Madison, WI.
Figure 33.3 Stromatolites in Shark Bay (W. Australia).
Figure 33.4 Cross section of modern algal stromatolite from Shark Bay (W. Australia).
Figure 33.5 Cross section of Precambrian stromatolite (ca. 1.3 Ba) from Belt Grp. in Australia.
- Burrows and tracks
Figure 33.6 Cambrian (ca. 600-500 Ma) sea scape - jellyfish and trilobites.
The sponge-like animals are representatives of the phylum Archaeocyatha
which is now extinct.
- Age of trilobites
Figure 33.7 Mid Cambrian (ca. 550 Ma) trilobite with missing appendages from Bohemia (CZ).
- Protozoa, Proriferia, Coelenterata, Annelida, Brachiopoda, Mollusca, Arthropoda,
Echindnodermata, Archaeocyatha
Figure 33.8 Mid Cambrian (ca. 550 Ma) fossilized sponge from Burgess Shale (CN).
- Bryozoans, Hemichordata, Chordata
Figure 33.9 Ordovician (ca. 500-425 Ma) graptolites (Hemichordata) - an important index fossil for Ordovician and Silurian rocks (ca. 500-400 Ma).
- No new animal phylla have appeared since
- Nautiloid cephalopod
Figure 33.10 Devonian (ca. 400-345 Ma) nautiloid cephalopod. Gas holding chambers are called septa.
- Maximum extent of seas over continents
Figure 33.11 Silurian (ca. 425-400 Ma) sea scape - corals (green, pink, purple), straight shelled nautiloids, snails, brachiopods (lower right), crinoids (red flowers), solitary corals (with pink and white tentacles) and sea weed (green).
Figure 33.12 Fossilized crinoid (limestone) from the Silurian (ca. 425-400 Ma).
- Vascular plants
- Age of eurypterids
Figure 33.13 Silurian (ca. 425-400 Ma) eurypterid with crinoids, organ pipe coral, etc.
- True fishes
- Age of fishes
Figure 33.14 Placoderm - a Devonian (ca. 400-345 Ma) sack fish with jawless mouth and air sack which is the forerunner of the lung.
Figure 33.15 Dimichthys after Cladoselache from fossils in Devonian (ca. 400-345 Ma) Cleveland Shale. Development of the jaw from a gill slit led to fierce predation.
- Rise of ammonites
Figure 33.16 Devonian (ca. 400-345 Ma) ammonoid (nautiloid cephalopod) with increasingly complex septa (called goniatitic).
- Extinction of graptolites and trilobites
- First amphibians and winged insects
Figure 33.17 Early amphibians (Stegocephalians) come onto land in Devonian (ca. 400-345 Ma).
- First forests (vascular plants)
Figure 33.18 Lower Devonian (ca. 400 Ma) landscape showing the early development of vascular plants.
Figure 33.19 Middle Devonian (ca. 370 Ma) landscape sees the development of gymnospermae (naked seed plants like conifers).
- Great diversification of plants (gymnospermae)
Figure 33.20 Pennsylvanian (ca. 300 Ma) coal swamps inhabited by Meganeura ==> a dragonfly with a wingspan of ca. 2 feet.
- Resurgence of corals
- Reptiles appear (amniotic egg)
- Great diversification of reptiles and insects
Figure 33.21 Diplouer ==> an early (Permian (ca. 280-230 Ma)) reptile from our continent.
Figure 33.22 Moschops - a mammal-like reptile and vegetarian of the Permian (ca. 280-230 Ma) of South Africa.
Figure 33.23 Eryops ==> a Permian (ca. 280-230 Ma) amphibian that attained lengths up to 6 feet.
- Rise of conifers
- Mass extinctions of marine amphibians (75%) and reptiles (80%)
- Limited floral changes
- Crustaceans are dominant arthropods
- Rise of oysters
- Quadrapedal and bipedal dinosaurs
Figure 33.24 Iguanodon of the Triassic (ca. 230-170 Ma) ==> first dinosaur discovered.
Figure 33.25 Dinosaur quarry in the Gobe Desert of Outer Mongolia being worked by a Polish expedition.
- Gliding pterosaurs
- Mammal looking reptile (Cynognathus)
Figure 33.26 Cynognathus ==> an early Triassic (ca. 230 Ma) mammal-like reptile, the size of a large dog, found in both South America and Africa. This critter doesn't look like it could negoitiate thousands of miles of deep ocean to populate both continents. More probably, these continents were connected at the time it existed.
- Palm like flora
- Land dinosaurs flourish
- Pterodactyls developed flight
- First bird (Archaeopteryx)
Figure 33.27 Left ==> Fossilized remains of the feathered bird, Archaeopteryx, from Solenhofen Limestone of Bavaria (from Earth Time and Life, by Barnes, John Wiley & Sons, Inc., 1988). Right ==> Jurrasic scene with Archaeopteryx and the flying reptile, Rhamphorhynchus, which had no feathers and a wingspan of ca. 3 feet. Also shown are palmlike cycads (from General Geology (5th ed.), by Foster, Merrill Publishing Co., 1988).
- Mammals rare and inconspicuous
Figure 33.28 Two Allosaurus feed on Apatosaurus in Late Jurrassic (ca. 130 Ma). Also pictured are a Brontosaurus (back), Stegasaurus (middle left), Brachiosaurus (lower right), and a small scavanging mammal.
- Rise of angiospermae (flowering plants)
Figure 33.29 Mesozoic (ca. 100 Ma) landscape and the development of angiospermae (flowering plants).
- Bees and butterflys radiate
- Age of dinosaurs
Figure 33.30 Exposed dinosaur bones in the Dinosaur Nat'l Monument Quarry near Vernal, UT. Bones are contained in the Morrison Fm. of Mesozoic/Jurrassic (ca. 150 Ma) age.
Figure 33.31 Exposed dinosaur bones in rocks of the Morrison Fm. at the Dinosaur Nat'l Monument Quarry near Vernal, UT.
Figure 33.32 Dinosaur tracks and ripple marks in rocks of the Morrison Fm.
Figure 33.33 Delta, UT ==> where Supersaurus was found in 1979. This dinosaur, the largest yet discovered, weighed ca. 80 tons and was over 80 feet in length. More than 50 new kinds of dinosaurs have been discovered since 1970!
Figure 33.34 Supersaurus quarry in Delta, UT.
Figure 33.35 Dinosaur Jim Jensen making plaster casts at the Supersaurus quarry in Delta, UT.
Figure 33.36 The great tyrant lizard ==> Tyrannosaurs Rex in Late Cretaceous (ca. 60 Ma) North America. This is the largest flesh eater ever on the planet, being ca. 50 feet in length and weighing ca. 10 tons.
Figure 33.37 Protoceratops ==> great first horned lizard of Late Cretaceous (ca. 60 Ma) Mongolia.
Figure 33.38 Triceratops ==> great three horned faced lizard weighing in at ca. 8 tons.
Figure 33.39 Brontosaurus ==> a vegetarian ca. 80 feet long and weighing ca. 50 tons.
Figure 33.40 Brontosaurus also could exploit aquatic environments.
Figure 33.41 Stegasaurus ==> a vegetarian quadruped weighing ca. 10 tons with spikes and plates for defence. It is believed to have had two brains. The one for thinking was the size of a walnut and 20 times smaller than the second brain which was an enlargement of the spinal cord controlling the movements of the hind legs and tail.
Figure 33.42 Late Cretaceous (ca. 60 Ma) marine lizards (Tylosaurus) with flying Pteranodon ==> the largest flying vertebrates of all time with 8 foot wing spans.
Figure 33.43 Pteranodon feeding their young in the Late Cretaceous (ca. 60 Ma).
- Mass extinctions of dinosaurs, ammonites, certain molluscs, cephalopods, bryozoa, echinoids,
planktonic foraminifera, etc.
- Age of mammals
Figure 33.44 With the collapse of the reptiles mammals radiated throughout the world initiating the Age of Mammals. An Early Tertiary (ca. 50 Ma) scene reveals the forerunner of modern hoofed animals ==> the Uintatherium.
Figure 33.45 An Early Miocene (ca. 25 Ma) scene includes the Moropus (3-clawed horse in upper left), and small primitive horses Parahippus (lower right).
Figure 33.46 Mammouth tusk, teeth and other remains recovered from a midwestern gravel pit where they had been buried ca. 5 Ma before present.
Figure 33.47 Mammoths ca. 5 Ma ago.
Figure 33.48 Wooly mammoths, musk oxen, Dall sheep, camels, and horses crossing the Bering land bridge in the Late Pleistocene (ca. 1 Ma).
Figure 33.49 Sabertooth tiger attack in South America during the Late Pleistocene (ca. 1 Ma).
Figure 33.50 Irish elk of the Late Pleistocene (ca. 1 Ma) ==> ancestor of the moose.