At this time mammoths, musk oxen, and dire wolves lived in the areas of the state not covered by glaciers. Local Native Americans have been devising mythical explanations for fossils or applying them for practical purposes thousands of years. The first scientific collection of local fossils began in the mid 19th century. Other important discoveries include the plant and insect fossils of Ruby Valley and "Deinonychus", which triggered the Dinosaur Renaissance. The Cretaceous Duck-billed dinosaur "Maiasaura peeblesorum" is the Montana state fossil. The fossil record in Montana stretches all the way back to the Precambrian. During the Late Precambrian, western Montana was covered by a warm, shallow sea. This sea was home to stromatolites and to bottom-dwelling marine life whose tracks on the benthic sediment would later fossilize. Montanan life of the time included arthropods, blue-green algae, conularians, fungi, and worms. Their fossils were preserved in what are now known as Glacier National Park. The worms left trace fossils such as burrow fillings and trails through the sediment. During the ensuing Cambrian period the state was still largely covered by sea water. Montana's Cambrian sea was home to algae, invertebrates, and even some of the first known vertebrates. Later, Cambrian trilobites left behind remains in Nixon Gulch, Horseshoe Hills north of Manhattan, Sawtooth-Lewis and Clark ranges west of Augusta, and the Bridger Range north of Bozeman. The sea eventually withdrew from the state and most of Montana's Silurian and Early Devonian sediments were lost to erosion. During the Late Devonian nearly the entire state was again inundated by the sea. Montana's Late Devonian sea was home to brachiopods, conodonts, crinoids, fish, molluscs, and sponges. Seas continued to cover the state into the Carboniferous period. At that time, the state was home to a bewildering array of cartilaginous fishes. Further into the Paleozoic, Mississippian brachiopods, bryozoans, and corals left behind fossils in the Bridger Range and at Shell Mountain south of Big Timber. Later in the Carboniferous, during the Pennsylvanian epoch, the sea began to retreat. Geological uplift was raising the elevation of the northern and northwestern regions of the state.