Chapter 3: What The Rocks Say

Question 1

Lagerstatte

Answer 1

a site with an abundant supply of unusually well-preserved fossils from the same period of time, often including soft tissues

Question 2

Burgess shale

Answer 2

a Lagerstatten in Canada that preserved fossils from the Cambrian period

Question 3

biomarker

Answer 3

molecular evidence of life in the fossil record; may include fragments of DNA, molecules such as lipids, or isotopic ratios

Question 4

stromatolites

Answer 4

layered structures formed by the mineralization of bacteria

Question 5

bacteria

Answer 5

one of two prokaryote domains of life; include organisms such as E. coli and other familiar microbes

Question 6

archaea

Answer 6

one of two prokaryote domains of life; resemble bacteria but are distinguished by a number of unique biochemical features

Question 7

eukarya

Answer 7

a domain of life characterized by unique traits including membrane-enclosed cell nuclei and mitochondria; includes animals, plants, fungi, and protists

Question 8

Ediacaran fauna

Answer 8

a group of animal species that existed between 575 and 535 million years ago

Question 9

chordates

Answer 9

members of a diverse phylum of animals that includes the vertebrates, lancelets, and tunicates. Chordates all have a notochord, a hollow nerve chord, pharyngeal gill slits, and a post-anal tail as embryos

Question 10

trilobites

Answer 10

extinct marine arthropods that diversified during the Cambrian period and gradually died out during the Devonian period

Question 11

notochord

Answer 11

a flexible, rod-shaped structure found in the embryos of all chordates. Notochords served as the first “backbones” in early chordates, and in extant vertebrates the embryonic notochord becomes part of the vertebral column

Question 12

prokaryotes

Answer 12

microorganisms lacking a cell nucleus or any other membrane-bound organelles. Prokaryotes comprise two evolutionarily distinct groups, the Bacteria and the Archaea

Question 13

tetrapods

Answer 13

vertebrates with four limbs (or descended from vertebrates with four limbs- so humans). Living tetrapods include mammals, reptiles, birds, and amphibians

Question 14

teleosts

Answer 14

a lineage of bony fish that comprises most living species of vertebrates. Teleosts include goldfish, salmon, and tuna. Teleosts can be distinguished from other fishes by unique traits, such as the mobility of an upper jawbone called the premaxillary

Question 15

synapsids

Answer 15

a lineage of tetrapods that emerged 300 million years ago and gave rise to mammals. Synapsids can be distinguished from other tetrapods by the presence of a pair of openings in the skull behind the eyes, known as the temporal fenestrae

Question 16

hominin

Answer 16

humans and all species more closely related to humans than chimpanzees