Name Fossils lab Mr. Kaiser

Transcription

1 Name Fossils lab Mr. Kaiser Purpose Fossils give us a window as to what life was like when it first appeared some billions of years ago. Some fossil remains can give us insight into how prehistoric plants and animals obtained food, reproduced, or even behaved. Geologists also use fossils to match layers of rock in different locations: They can match by how similar the fossils in each rock layer are. This information can help us understand when different rock layers formed. Environmental interpretation: A fossil can tell us what kind of environment existed when it was formed. For example, if you find fossil marine animals someplace, then you know that there must have once been an ocean there. Fossils are a major type of evidence for understanding evolution. Using information from fossil evidence, scientists can develop a Tree of Life to describe relationships between organisms

2 Vocabulary Fossil = physical remains of long dead organisms. In a fossil, nearly all of the original organic material is gone, and has been replaced by minerals. Fossilisation is the process by which a dead animal s body slowly loses organic molecules, and how they are replaced by minerals. MYA = million years ago Materials Geological samples (handed out by teacher) and web resources: Geologic eras of history science/268 2/geologic eras/ How fossils are made the living environment/evolution/fossils/ Dating fossils and rocks science/268 2/dating rocks and fossils/

3 Learning Standards Massachusetts Science Frameworks Curriculum, High School HS LS4 1. Communicate scientific information that common ancestry and biological evolution are supported by multiple lines of empirical evidence, including molecular, anatomical, and developmental similarities inherited from a common ancestor (homologies), seen through fossils and laboratory and field observations. College Board Standards for College Success: Science Objective ES.3.2 Rock and Fossil Records. Students understand that the rock and fossil records provide evidence of the evolution of Earth s environment and the associated changes in life over time. ESM PE Infer the environment in which a fossil formed. Inference is based on the physical characteristics of both the fossil and the rock in which the fossil was found. ESM PE Determine, using the law of superposition and using cross sectional representations of fossil bearing rocks, the relative ages of fossils from different locations. ESH PE Explain, based on evidence found in the rock and fossil records, species extinction and evolution. Fossils Common name Scientific name Geological era Time in years Location Trilobite From the Ductina genus Devonian 420 to 360 MYA This sample is from 380 MYA Guangxi province, China Facts about the organism More facts

4 Common name Scientific name Geological era Time in years Location Ammonite Each kind of ammonite is in the phylum Mollusca Class: Cephalopoda Subclass: Ammonoidea Upper Jurassic 190 MYA Poitou, France Facts about the organism More facts What are molluscs? Invertebrate animals with a three part body plan First let s figure out what an invertebrate is: Vertebrates = animals with a backbone (spine) and a nervous system running down it Invertebrates = animals without a backbone (spine), although they usually do have a nervous system

5 Molluscs have three basic body parts (a) mantle = large body mass, with internal organs. Mantle is usually wholly or partly enclosed in a calcium carbonate (chalk) shell. (b) radula = fleshy structure used for feeding, often compared to a tongue. Covered in tiny denticles (miniature teeth.) Only found in molluscs. A radula is in all mollusks (except the bivalves.) (c) a nervous system (almost all animals have a nervous system)

6 Several categories of molluscs I. Gastropods stomach foot. Includes snails, slugs, limpets, and sea cucumbers.

7 II. Bivalves foot projects from shell. Includes clams, oysters, scallops, mussels (there are also a few other mollusca categories)

8 III. Cephalopods head foot. Includes octopi, squid, cuttlefish, and nautilus. Image by Mark Belan They all have: bilateral body symmetry a prominent head A set of tentacles IV. There are a few other mollusca categories; you can look them up if you like.

9 Common name Scientific name Geological era Time in years Location Megalodon Carcharodon megalodon Miocene, in the Cenozoic era 7 MYA Morgan River, South Carolina Facts about the organism More facts

10 Common name Scientific name Geological era Time in years Location Freshwater snails Elimia tenera Facts about the organism More facts Found in a rock called Turritella agate,

11 Common name Scientific name Geological era Time in years Location White corral (modern) Facts about the organism

12 Common name Scientific name Geological era Time in years Location Facts about the organism More facts Common name Scientific name Geological era Time in years Location Facts about the organism More facts

13 Name _(teacher copy) Geology samples Mr. Kaiser Hematite, Mexico The mineral form of iron(iii) oxide (Fe2O3), one of several iron oxides. Mined as the main ore of iron Amethyst quartz Quartz with mica Leopard Skin, Japan Sidewalk concrete For all practical purposes, this is a man made sedimentary rock

14 Slag from copper refining Made at the Revere copper melting in Winthrop/Point Shirley History copper works.html What is slag? Copper slag Red Tiger Eye, China Mozarkite chert from Missouri Pumice/Lava, Banderas volcano

15 Citrine (large sample) on calcite Citrine is a variety of quartz whose color ranges from a pale yellow to brown due to ferric impurities. Most is from Brazil. An altered/heated amethyst (which is a type of quartz). The discontinuity is a cooling/sudden temperature change phenom. Fine grained white is rapid or instant cool. Forms the crust which insulated the inside and allows much slower cooling which forms larger crystals. Basically white milky quartz on outside separated from more crystalline quartz by discontinuity. Calcite (large sample) translucent crystals emerging from a small rocky base [Or could this be gypsum?] CaCO 3 Calcite is one of the most common and widespread minerals. It is a principal component of most sedimentary carbonate rocks (limestone, chalk, travertine, etc.) but occurs in metamorphic (marble, hydrothermal veins) and igneous rocks (carbonatite) also. One of the raw materials for making cement the first is likely calcite. but if you can do a hardness/acid test it would reveal more. If it fizzes in mild acid, then it's probably calcite, maybe dolomite. If no fizz then probably gypsum. If a knife scratches it, then it is calcite. A fingernail will scratch gypsum. if it doesn't scratch, quartz. The lenses of ancient trilobite eyes were made of calcite crystals! Geode (large) Geodes occur in certain sedimentary and volcanic rocks. They are of sedimentary origin Hollow, vaguely spheroid to oblate masses of mineral matter (which may include crystals)

16 Form either by the filling of vesicles in volcanic to sub volcanic rocks by minerals deposited from hydrothermal fluids or Form by the dissolution of igneous nodules and partial filling by the same or other minerals. Those other minerals come from nearby water Usually have a chalcedony (cryptocrystalline quartz) shell Lined internally by various minerals, often as crystals. Most commonly quartz, but also can be calcite, pyrite, kaolinite, sphalerite, millerite, barite, celestite, dolomite, limonite, smithsonite, opal, chalcedony, found mostly in basaltic lavas and limestones.