Chapter 1 Paleontologist someone who studies ancient organisms Scientific literacy many children s first exposure to scientific concepts Paleobiology the study of ancient life Scrotum humanum first proper scientific name given to a dinosaur actually distal end of megalosaur thigh bone Thomas Jefferson was a fossil fanatic Mr Mammoth Mosasaurus 40 foot long sea monster not a dinosaur found in Holland Baron George Cuvier studied giant sloth fossils concept of extinction Reverend William Buckland credited with describing the first scientifically valid dinosaur in 1824 o Named his dinosaur megalosaurus big reptile small t rex Gideon Mantell surgeon found iguanodon o Iguanadon iguana tooth o First described herbivorous plant eating dinosaurs Sir Richard Owen great British comparative anatomist o Reptiles sauropsids scaly skinned terrestrialized living on land animals that lay hard shelled eggs o Fearfully Great Reptiles 1842 giant possessing upright stances non aquatic 1 having more than two sacral vertebrae backbones fused in the hip region Archosaurian reptiles o Includes crocodilians and pterosaurs extinct flying reptiles and dinosauromorphs Dinosauromorphs Extinct dinosaur like reptiles Archosaurs crocodiles pterosaurs dinosaurs and the other Archosaurians such as dinosauromorphs distinguished by o Teeth and sockets replaced throughout life o Pterosaurs and dinosauromorphs have hinge like ankles Ankle where the pivot is in the middle of the cluster of bones o Erect posture dinosauromorphs are closest relatives to dinosaurs Dinosaurs have three key factors o Three of more sacral vertebrae fused backbone o Hands with the three main fingers o Perforate acetabulae Two major groupings of dinosaurs are o Ornithischians bird hips wit h pelvic bone shaped like those of birds NOT related to birds o Saurischians with pelves like lizards lizard hips Fossil Feud Othniel Charles Marsh Edward Drinker Cope described hundreds of dinosaurs from only fossil scraps that were already named Louis Dollo hired to study Iguanodon 2 o Nose horn was actually thumb spike o First person we called paleobiologist a person interested in the lives of dinosaurs their ecosystems etc Deinonychus terrible claw dinosaur renaissance o Small large brained and agile with streamlined body and tendon stiffened tail that provided teeter totter like counterbalancing Robert Bakker challenged that dinosaurs were more like modern birds that had been previously thought o Similar athletic build and posture o As a result interest in dinosaur research soared Chapter 2 The very first dinosaurs were small bipedal carnivorous animals that first show up 238 million years ago Mesozoic Era o Age of Dinosaurs Three divisions periods of the Mesozoic Era o Triassic Period 251 200 million years ago Oldest dinosaurs show up midway through this period o Jurassic Period 200 146 million years ago Time of very largest dinosaurs o Cretaceous Period 146 65 54 million years ago when T Rex ruled dinosaurs went extinct 65 54 million years ago end of cretaceous period 3 Uranium 235 best isotope for dating rocks from the Age of Dinosaurs o Breaks down into Lead 207 Half life the amount of time it takes for half of the original material to break down Arid in equatorial regions much like Florida in middle latitudes o Closer to the poles it was cool wet and rainy During Triassic period one super continent known as Pangea Plate tectonics continents moved apart o Continental movements are driven by volcanic seafloor spreading in the oceans No ice caps at the poles Because of this there were more free water in the oceans than there is today and a greater portion of the continents were covered by water Gymnosperms dominated world s dryer ecosystems o such as pine trees conifers cypress trees cycads ginkgo trees etc o great height chemical defenses thick bark and touch foliage less ground cover than there is today angiosperms flowering plants The world became more vegetated with ground cover all over and closed forests of deciduous trees became abundant The earliest crocodilians were not like those today They were small agile terrestrial predators Deinosuchus terror crocodile 32 foot long 4 o These animals became giant not by growing fast but by growing at the same rate as living dinosaurs o Simply extended length of their rapid growth phase like humans experience in teenage years for an extra 20 years basically went through puberty for 20 years First turtles from the Triassic period were fully terrestrial and had teeth Sea Monsters o Ichthyosaurs reptiles that looked and swam like dolphins o Plesiosaurs long necked supposed loch ness monster like sea turtles o Mosasaurs animals Cuvier used to support his extinction theory sea going relatives of living monitor lizards like Komodo dragon Quetzalcoatalus 36 foot long wing span largest known pterosaur toothless Pterosaurs bat like beaks ate dead dinosaurs Period Mammals appeared about the same time as the dinosaurs in the Late Triassic o Rat or weasel like and mouse to opossum sized o Remained throughout the entire 173 million tenure of dinosaurs Fossils are evidence of ancient life Another category of dinosaur fossils knows as trace fossils o Trace fossils are the primary means by which paleontologists learn about dinosaur biology 5 To become fossilized remains buried rapidly under sediments from rivers most common windblown sand fairly common or volcanic ash rarely Sedimentary rocks rocks formed from sediments including organic derivatives Igneous rocks those from volcanoes Metamorphic rocks sedimentary or igneous rocks that have been deformed by the pressures of the earth Bones are composed of the original calcium phosphates the hard mineral in bones Animals only very rarely become fossilized Most dinosaurs are known only from single partially complete specimens badlands land with little vegetation so it is easy to find fossils o found throughout the Midwestern U S Alberta and Canada Eastern Asian and parts of Africa Chapter 3 Two types of dinosaurs Chapter 1 o Saurischians lizard like hip bones meat eaters and the herbivorous long necked sauropod giants o Ornithischians bird like hip bones beak herbivorous armored dinosaurs horned dinosaurs duck bills etc First ornithischians o Middle Triassic period 6 o 238 million yeas ago o small bipedal animals Note All dinosaurs were not giants and the earliest forms were small Thyreophora shield bearers o Armor in their skin bones in the skin are referred to as
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