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HUNTING FOR FOSSILS IN LOUISIANA. The Mission of the LSU Museum of Natural Science. Acquisition, Preservation, and Study of research collections to generate knowledge of: Regional and global biodiversity, Geological history, and Human history and prehistory
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The Mission of theLSU Museum of Natural Science • Acquisition, • Preservation, and • Study of research collections to generate knowledge of: • Regional and global biodiversity, • Geological history, and • Human history and prehistory for the benefit of the people of the state, the nation, and the world.
Divisions of the LSU MNS • 7 main fields of RESEARCH • Ornithology (Birds) • Genetics • Ichthyology (Fishes) • Mammalogy • Herpetology (Reptiles and Amphibians) • Paleontology • Anthropology (Archaeology and Ethnography) • EDUCATION
THE PALEONTOLOGY COLLECTIONS
Invertebrate Paleontology: Palynology Dr. Sophie Warny What is palynology? • Palynomorphs = • both plant and animal structures • microscopic in size (from about 5 µm to about 500 µm) • made of compounds that are highly resistant to decay • abundant in most sediments and sedimentary rocks • can be extracted by chemical processing (acids digestion & sieving) Spores Pollen grains Dinoflagellate cysts Acritarchs Leiospheres
What is it used for? • * Biostratigraphy and geochronology: • correlate strata • determine the relative age of a bed or formation * Palaeoecology and climate change: - used to reconstruct past vegetation (land), hence palaeoclimatic conditions - used to infer past environmental conditions (marine) * Criminology (forensic palynology) * Archaeology (past agriculture) * Commercial (melisopalynology, culture prediction) * Medical field (allergies)
Vertebrate Paleontology Dr. Judith Schiebout Collections: • Over 17,000 specimens from over 1000 localities with emphasis on Louisiana. • Research statement: Dr. Schiebout's focus is on: • Paleoecology • Biostratigraphy and paleogeography of southern North America and China in the Tertiary • Early and middle Tertiary mammals • The Cretaceous-Tertiary and Paleocene-Eocene transition • Louisiana fossil vertebrates, particularly in the Miocene
Large collection of middle Tertiary mammals from the Fort Polk region Dr. Schiebout excavates the lower jaw of 13.5 million year old herbivore at Fort Polk.
Large collection of Tertiary fossils including this whale: Vertebrae and ribs of the Eocene whale Basilosaurus at Montgomery Landing, Louisiana. The Museum holds the front 1/3 of the skeleton including one of the most complete skulls known for this whale.
Large collection of Tertiary mammals from Tunica Hills, such as early elephant, rhino, hedgehog and camel relatives. Also: Dr. Ting holding an early Pliocene (Ice age) mastodon tusk and palate from the Tunica Hills.
Allosaurus in Howe-Russell building The biggest, most abundant meat-eater during the late Jurassic period in America, about 150 million years ago. It probably preyed upon large, plant-eating dinosaurs, like iguanodons. The allosaur¹s serrated teeth, while smaller than those of the T. rex, were as capable of tearing free large quantities of meat. • -walked on two powerful legs • massive tail • short arms with 3-fingered hands • sharp claws up to 6 inches long • 38 feet long and 16.5 feet tall • weighed about 1400 kg • 3-ft long skull • sharp, serrated teeth 2 to 4’’ long
2. ACTIVITY: HUNTING FOR FOSSILS IN LA Goals: - help you identify some of the fossils - describe the history of their journey
1 Gravel can be found in many places in Louisiana 2 It occurs naturally in stream and river banks 3 Gravel is just a loose mixture of rock fragments 4 We rarely wonder where it came from… 5 We don’t often sit down and look for unusual shapes or colors 6 But… LA gravel is made up of rocks formed millions of years ago 7 On the sea bottom 8 If we look closely, we can often find distinct impressions of ancient marine life
- The earth was formed approximately 4,600 million years ago. - Geologists have divided the earth’s history into intervals - The period during which the fossils found in Louisiana gravels lived was between 408 and 330 million yearsago. - The fossils in the Louisiana gravels lived during part of the Paleozoic Era, in the Silurian, Devonian, and Mississippian Periods.
- Study rocks -> in what environment sediments were deposited. -> Recognize past rivers, beaches, deltas, inshore/offshore trends. - Studies of Paleozoic rocks show that the North America of those times was far from that of today (it was covered by a shallow sea).
This is a scene of how the sea bottom may have looked at this time. In this sea, life proliferated with coral reefs, fields of sea lilies, shellfish, moss-like bryozoans, insect-like trilobites and other animals and plants.
How did these fossils, buried hundreds of millions of years ago in the North, arrived as gravels in Louisiana today? - Buried rocks uplifed - Weathered and broken up (erosion) by wind, water, and ice. - Transported by glaciers between 1.8 and 10,000 years ago (Pleistocene) as the earth underwent a series of glaciation. - At these times, ice covered much of North America, large volumes of rock were eroded. - Some of the Paleozoic rock was broken up by ice. - Then transported south to Louisiana by rivers when the ice melted.
Paleozoic life - The marine invertebrates! Arthropodes Insects, trilobites Brachiopoda Shells Bryozoa Moss-like animals Cnidaria Corals (tab. & rug.) Echinodermata Starfish, sand dollars Mollusca Snails, clams - The shape, structure, and markings of a fossil = characteristics - Used to classify them according to the system shown above. - Because Louisiana gravels contain relatively few different types of fossils, let’s look at what each fossil type looks like.
Crinoid remains preserved in gravel are mostly hollow molds or filled molds (casts). Look for circular shapes with a central hole and fine radiating grooves. Look also for rectangular and columnar shapes, sometimes stacked.
Rugose: - solitary or colonial - extinct group of corals - abundant in Ordovician/Permian - some were a meter in length Tabulate: - common in gravels - differences with rugose: a) all colonial; b) radiating septa reduced or absent c) main structure = horizontal plate (tabulae) that looks like ‘honeycomb’ appearance.
Bryozoans are: - moss-like animals - grow in fan-shaped, branching, or encrusting colonies. - look somewhat like corals; - but, more delicately built, - with a fan-shaped structure. In gravels: look for delicate fan shapes.
Mollusca: Bivalva • - clams, oysters, mussels • - shells = 2 pieces (valves) • - joined by an elastic ligament • shells: • = mirror images of each other • = ! bilateral symmetry • Difference with brachiopods: • Each valve is bilaterally • symetrical.
Mollusca: Gastropoda - soft body - a large foot enclosed in: - a single, non-chambered, coiled shell. The shells may be shaped as a: - dome or - cone The gravels usually contain casts of the inside coils of the gastropods. Look for these coiled cross-sections.
Brachiopoda - shells - attached to the sea bottom by a fleshy stalk or pedicle. - a hole through which this stalk passed - it can often be seen on the larger of the two valves - brachiopods always: * have different sized valves, * each valve is bilaterally symmetrical. * bivalves do not have a pedicle hole.
Trilobites: - extinct marine arthropods (insect-like animals) - lived on the seafloor. - they have a three-part body plan that consists of a * cephalon (head), * a thorax, and * a pygidium (tail) with a chitinous exoskeloton. The thorax is fairly flexible and when preserved, the trilobites are often found curled up like modern rolly-pollies. They are rarely found preserved in gravels.
General Info & Tours Monday-Friday 8:00 am - 4:00 pm FREE! Scheduling Materials Rules Parking …
Activities for Self-guided tours • The MNS book is available: • in French thanks to: • … Anne-Sophie & Stanislas Dubois • in Spanish thanks to: • … Ana Morales
Learn about mastodons!
5. HANDS ON ACTIVITIES Learn about the different types of fossils