What do paleontologists look for in fossils?
Paleontology is the study of the history of life on Earth as based on fossils. Fossils are the remains of plants, animals, fungi, bacteria, and single-celled living things that have been replaced by rock material or impressions of organisms preserved in rock.
What did Gingerich name the ancestral whale he found?
Gingerich devoted years of work to trying to locate whale fossils that would show what sort of ankle bones they and their ancestors possessed. In 1991, he found a 40 million-year-old skeleton of a creature called Basilosaurus, an ancient whale that resembled a sea snake.
How do archaeologists find fossils?
To find fossils, paleontologists first carry out an operation called prospecting, which involves hiking while keeping one's eyes focused on the ground in hopes of finding fragments of fossils on the surface.
How do scientists identify fossils?
A paleontologist collects as many fossils as possible from a rock or sediment. Once the fossils are prepared by scraping and cleaning, they are sorted by geometry. Fossils with very similar geometry are assumed to belong to a single species.
What was unusual about the fossil skull that Phil Gingerich discovered in Pakistan?
What was unusual about the fossil skull that Phil Gingerich discovered in Pakistan? He found a skull with an expanded bony bulb, similar to a structure found in a modern whale skull. Fossils revealed what evolutionary changes in the front legs of whales? They turned into flat flippers.
What did Dr Gingerich ultimately find that helped confirm the phylogeny of ancient whales?
Professor of Geological Sciences In 2000, he found fossils that confirmed the assertion by molecular biologists that whales evolved not from mesonychids, extinct wolf-like animals, but from artiodactyls, the ancestors of hippos and camels.
How we determine the age of rocks?
The age of rocks is determined by radiometric dating, which looks at the proportion of two different isotopes in a sample. Radioactive isotopes break down in a predictable amount of time, enabling geologists to determine the age of a sample using equipment like this thermal ionization mass spectrometer.
What are fossils geography?
Fossils are the preserved remains of plants and animals whose bodies were buried in sediments, such as sand and mud, under ancient seas, lakes and rivers. Fossils also include any preserved trace of life that is typically more than 10 000 years old.
How do geologist determine the age of rocks?
The age of rocks is determined by radiometric dating, which looks at the proportion of two different isotopes in a sample. Radioactive isotopes break down in a predictable amount of time, enabling geologists to determine the age of a sample using equipment like this thermal ionization mass spectrometer.
What does geology consist of?
Geology is the science that studies the Earth's physical structure and substances, the history of rocks, the processes that act on them and the most economic way to use the world's resources. Geology involves methods and knowledge from biology, chemistry, physics and mathematics.
What unexpected fossil evidence of whale evolution did Phil Gingerich discover when he found Basilosaurus fossils in the valley of the whales?
What unexpected fossil evidence of whale evolution did Gingerich discover when he found Basilosaurus fossils in the Valley of the Whales? He found a pelvis and a back leg, including a knee cap and toes.
What fossilized ancient species of whales did Dr Gingerich find that had hind legs?
Basilosaurus isis The most surprising aspect of the discovery, Dr. Gingerich said, was that functioning hind limbs were found on a species of whale, Basilosaurus isis, that lived 10 million years after the transition from land to sea had occurred.
What where some of the key findings that led researchers to determine that whales evolved from terrestrial mammals?
The new bones, dubbed Pakicetus, proved to have key features that were transitional between terrestrial mammals and the earliest true whales. One of the most interesting was the ear region of the skull. In whales, it is extensively modified for directional hearing underwater.
How did scientists form the geologic time scale?
The geologic time scale was developed after scientists observed changes in the fossils going from oldest to youngest sedimentary rocks. They used relative dating to divide Earth's past in several chunks of time when similar organisms were on Earth.
What types of information did geologists use to develop the geologic time scale?
Scientists first developed the geologic time scale by studying rock layers and index fossils worldwide. With this information, scientists placed Earth's rock layers in order by relative age. Later, radioactive dating helped determine the absolute age of the divisions in the geologic time scale.
Why do geologists use the geologic time scale?
Scientists use the geologic time scale to illustrate the order in which events on Earth have happened. The geologic time scale was developed after scientists observed changes in the fossils going from oldest to youngest sedimentary rocks.
How are sedimentary rocks formed?
Sedimentary rocks are formed from deposits of pre-existing rocks or pieces of once-living organism that accumulate on the Earth's surface. If sediment is buried deeply, it becomes compacted and cemented, forming sedimentary rock.
What do geologists use?
Geologists use a lot of tools to aid their studies. Some of the most common tools used are compasses, rock hammers, hand lenses, and field books.
What geologists do?
Geologists study the materials, processes, products, physical nature, and history of the Earth. Geomorphologists study Earth's landforms and landscapes in relation to the geologic and climatic processes and human activities, which form them.
What did Gingrich discover that altered our concept of whale evolution?
It was evidence that whales had once been 4 legged animals. What unexpected evidences of whale evolution did Gingerich discover when he found Basilosaurus fossils in the Valley of the Whales? when they swim, they flex their spines up and down similar to running land mammals.
Which piece of evidence supports the hypothesis that cetaceans whales evolved from terrestrial mammals as opposed to some aquatic organisms?
What evidence supports the hypothesis that whales evolved from land-dwelling mammals? The femur bone, a vestigial structure, that is still present in whales supports the hypothesis that whales evolved from land-dwelling mammals.
What was unusual about the fossil skull that Gingerich discovered in Pakistan?
What was unusual about the fossil skull that Phil Gingerich discovered in Pakistan? He found a skull with an expanded bony bulb, similar to a structure found in a modern whale skull.
What do fossils tell us about whale evolution?
The fossils help reveal the whale's deep history, from extinct species that originally lived on land to today's cetaceans. And by knowing their past we can help ensure that these magnificent creatures survive the many threats they face in today's world.
How do scientists learn about organisms of the past when studying fossils?
The fossil record provides evidence for when organisms lived on Earth, how species evolved, and how some species have gone extinct. Geologists use a method called radiometric dating to determine the exact age of rocks and fossils in each layer of rock.
What are geologic time periods based on?
In the Geologic Time Scale, time is generally divided on the basis of the earth's biotic composition, with the Phanerozoic Eon (i.e. the Paleozoic, Mesozoic and Cenozoic Eras) representing the period of Earth's history with advanced life forms, and the Pre Cambrian (or Proterozoic and Hadean Eras) representing the …
How do geologists separate time into?
Eons are divided into smaller time intervals known as eras. In the time scale above you can see that the Phanerozoic is divided into three eras: Cenozoic, Mesozoic and Paleozoic. Very significant events in Earth's history are used to determine the boundaries of the eras. Eras are subdivided into periods.
What is the geologic time scale based on?
the geological rock record The geological time scale is based on the the geological rock record, which includes erosion, mountain building and other geological events. Over hundreds to thousands of millions of years, continents, oceans and mountain ranges have moved vast distances both vertically and horizontally.
How are minerals formed in igneous and metamorphic rocks?
In igneous and metamorphic rocks minerals may occur in the cracks, crevices, faults or joints. The smaller occurrences are called Veins and the larger is called Lodes. In most cases, they are formed when minerals in liquid/molten and gaseous forms are forced upward through cavities towards the earth's surface.
What is the collective term for all the chemical physical and biological changes that take place after sediments are deposited?
Facies is a collective term for all of the chemical, physical, and biological changes that take place after sediments are deposited during and after lithification. 28.
What do geologists do quizlet?
Geologist study the processes that create Earth's features and search for clues about Earth's history. They also study the chemical and physical characteristics of rock, the material that forms Earth's hard surface.