Introduction to Paleobiology and the Fossil Record

560 GLOSSARY
endostyle “inside pen”; mucus organ in the gut
of chordates.
endosymbiont “inside together life”; an organism
that lives in symbiotic relationship with
another, and is entirely enclosed within its
structure.
endotherm “inside heat”; an animal that controls
its body temperature by internal means (cf.
ectotherm).
enrollment rolling up.
enteron “gut”; the gut and respiratory cavity of
a cnidarian.
epifauna “top fauna”; animals that live on the
seabed, not within the sediment (cf. infauna).
epirelief “top relief”; a trace fossil on the top of
a bed (cf. hyporelief).
epitheca “top-case”; the upper half of a diatom
theca (cf. hypotheca).
epithelium (pl. epithelia) cell layer forming outer
tissues.
epoch a division of geological time, such as
Eocene, Oligocene or Miocene; a subdivision of
a period, and composed of several stages.
equilibrium “equal balance”; a fixed level.
esophagus the part of the gut between the mouth
and the stomach.
eukaryote “well kernel”; single- and multicelled
life form with a nucleus, including algae, fungi,
plants and animals (cf. prokaryote).
eumetazoans clade including all the major metazoan
groups except for the sponges.
euryotopic “wide place”; of wide ecological
preferences (cf. stenotopic).
eustatic “well standing”; relating to simultaneous
worldwide changes in sea level.
eutrophication “healthy nutrition”; oxygen starvation,
usually in a lake, caused by decaying
algae after an algal bloom.
evenness the approach to equal abundance of
species within a community (cf. dominance).
evolute “rolling out”; coils of a gastropod or
cephalopod shell that are all at least partially
exposed (cf. involute).
evolution “unrolling”; change in organisms
through time.
exceptional preservation preservation of soft
parts and of soft-bodied organisms.
exine the tough outer wall of pollen and
spores.
exogastric “outside the stomach” (cf.
endogastric).
exogenic “formed outside”; formed on the
surface of the sediment, such as a trail (cf.
endogenic).
exoskeleton “external skeleton” (cf.
endoskeleton).
exponential a curve that indicates geometric
growth, where the y-value increases ever-faster
in proportion to the x-value.
extant phylogenetic bracket (EPB) the observation
that ancestors included, or bracketed, by
living forms, will likely have possessed any
shared characters of the bracketing forms.
extinction the disappearance of a species, genus
or family.
extremophile organism adapted to life in extreme
environmental conditions.
exuviae “thrown off”; cast-off molted skins.
facial suture the dividing line on the cephalon of
a trilobite along which the exoskeleton splits
during molting (cf. free cheek).
facies a characteristic association of sedimentary
features that may indicate a particular environment
of deposition.
facies fossil a fossil that is characteristic of a
particular sedimentary facies.
family a division in classification; contains one
or more genera, and is contained in an order.
fasciculate “bundle-like”.
fauna the characteristic animals of a particular
place and time.
fecal referring to excrement or dung.
femur the thigh bone (cf. fibula, tibia).
fibula one of the shin bones (cf. femur, tibia).
finite element analysis (FEA) an engineering
technique that models stresses and strains in
complex structures.
firmground a sea or lake floor composed of
semiconsolidated calcareous sediment (cf.
hardground).
flagellum (pl. flagella) “whip”; hair-like organelle
in a eukaryote cell that is used for
swimming.
flattening compression of a fossil by pressure
from above.
flora characteristic plants of a particular place
and time.
fluvial, fluviatile referring to rivers.
flysch an accumulation of sandstones and mudstones,
generally formed in a deep basin from
turbidity flows.
fodinichnion (pl. fodinichnia) “feeding trace”.
foliated “leaf-like”; consisting of thin layers.
food chain unidirectional links between food
and consumer within a community.
food pyramid the pattern of biomass distribution
within a community, typically with large