Paleo 200 Midterm 1 -Prof Curated

Deterrents

Discourage predators from choosing to attack in the first place
E.g.,turtle shells, large size in sauropods, etc

Crypsis

The ability of an animal to avoid detection by predators through camouflage, hiding behaviours and odour masking chemicals.
- Difficult to judge from fossil evidence (scent and colour do not fossilize)
- More common in small animals

Argentinosaurus

Sauropod which relied on its large size to deter predators.
- Could trample and hit with tails

Triceratops

Three-horned dinosaur who may have used its frill to intimidate predators and horns as weapons against predators.

Anodontosaurus

An ankylosaur which protected itself from predators with osteoderms and a tail modified into a club.

Stegosaurus

Herbivorous ornithischian dinosaur with a row of bony plates along its back and a spiked tail probably used as a weapon

Finite Element Analysis

Computer simulations that examine stress dispersal through 3D objects, used by palaeontologists to evaluate hypotheses about the function of dinosaur adaptations.

Euoplocephalus

An ankylosaur dinosaur with a tail club that Finite Element Analysis concluded could have been used as a weapon.

Stereoscopic vision

The ability to see an object with both eyes at once, allowing the animal to better perceive depth.

Dry Island Buffalo Jump

A bone bed site in Alberta containing the remains of more than 20 individuals of Albertosaurus.

Agonistic Behaviours

Fighting and aggressive displays between members of the same species

Carnivore Hunting Styles

- Ambush
- Stalk and pursue
- Pursue over long distances until tiring them out

The fighting dinosaurs

An incredible fossil from Mongolia which apparently preserves a Protoceratops and Velociraptor locked in combat.

Interspecific interactions

A relationship between individuals of two or more different species.

Intraspecific interactions

A relationship between members of the same species.

Ritualized agonistic combat

Competition between two individuals of the same species that determines which is the strongest without either combatant risking serious injury.

Stegoceras

Small pachycephalosaur which may have engaged in ritualised agonistic combat using its thick-domed skull.

Herding

A defensive behaviour in which prey band together to benefit from the many alert senses of the collective group.

Cooperative hunting

Hunting behaviour in which individuals work together to catch prey

Monospecific bonebeds

Large accumulations of fossil bones that are all from multiple individuals of the same species.

Pinacosaurus

Ankylosaur for which monospecific bone beds of juveniles have been found.

Non lethal face biting

Common agonistic behaviour among modern carnivores; supported in dinosaurs like tyrannosaurs by skull pathologies.

Paleopathologies

Include healed injuries or other evidence of diseases such as infections, cancer, or arthritis

Amniotes

A group of tetropods that lay eggs equipped with a special water-tight membrane layer called an amnion.

Histology

The study of bone microstructure as it relates to bone growth

Line of Arrested Growth (LAG)

A dark band visible in a histological cross-section of a bone that formed during a time when the bone was not growing; LAGS are generally assumed to form annually in response to regular seasonal periods of food scarcity

External Fundamental System

A closely spaced series of LAGs, towards the outside of a bone section, formed as growth slows and, eventually, stops.

Ontogenetic Changes

Anatomical changes that occur during an individual's life (growth).

Non-isometric ontogenetic changes.

Changes in the relative proportions of an animal
as it grows, that are not simply changes
resulting from a general increase in size. (E.g. Fast growth of horns vs slow growth of body).

Isometric ontogenetic changes

Changes in absolute size but not
proportions of an animal.

Sexual Dimorphism

Differences between males and females of a given species, beyond genitalia.

Medullary Bone

Bone that stores calcium in preparation for laying eggs- useful in identification of female dinosaurs.

Osteocyte

Bone cell, formed by bone-creating cells (osteoblasts) becoming surrounded and trapped by the product they secreted.

Predator satiation

A reproductive strategy where herbivores produce lots of offspring and provide little to no parental care, as opposed to producing fewer offspring and protecting them. E.g. Sea Turtles or Sauropods

Lamellar bone

Striated, regularly structured bone tissue which is more visible in the bones of young dinosaurs.

Haversian bone

Also called 'secondary bone'; this is bone tissue that has been secondarily remodelled during the dinosaur's lifetime- more evident in older dinosaurs.

Vascularity

Lots of spaces in bone tissue, due to the presence of blood vessels required for bone formation when the animal was allowed. More evident in the bone tissue of young dinosaurs.

Serrations

Small sharp bumps on a predator's tooth (e.g. tyrannosaurids) that are arranged
in a line that usually runs from the tip to the
base of the tooth.

Frugivore

Animal that primarily eats fruit.

Piscivore

Specialized carnivores that
primarily eat fish.

Insectivore

Specialized carnivores that
primarily eat insects.

Omnivore

Animals that eat significant amounts of both meat and plants

Durophagy

The eating behaviour of animals adapted to crush bones.

Resorption

When bones and teeth are broken down while an animal is alive and the minerals are transferred back into the blood

Dental Battery

Dense arrangement of teeth found in the jaws of
hadrosaurs and ceratopsians

Dentine

Hard tissue that helps to form teeth.

Gastroliths

Small masses of little stones found in ribcages of some herbivorous dinosaurs. Form part of the 'gastric mill' that helps some dinosaurs and birds grind up plant matter.

Dromaeosaurs

A group of theropods with an enlarged and sickle-shaped claw on each foot and stiffened tails; lived during the Cretaceous period; examples: Velociraptor, Utahraptor, Deinonychus.

Spinosaurs

A group of theropods with skulls
that strongly resemble those of crocodiles. Thought to be piscivores.

Alvarezsaurs

A group of small theropods with short front limbs and compact hands. Alvarezasaurs are thought to have been insectivores.

Tyrannosaurs

A group of theropods that evolved late in the history of dinosaurs and have reduced front limbs and robust skulls, with large serrated teeth.

Scavenging

The consumption of an already dead animal by a carnivore that did not play a part in killing it.

Cololites.

Fossil gut contents.

Coprolites

Fossil poop!

Taphonomy

The study of all natural processes that involve
an organism after it dies -- this includes how it
decays, is scavenged by other organisms,
becomes fossilized, and erodes

Disarticulated

A skeleton that is separated into its various components

Plastic deformation

Taphonomic alteration to the shape of a fossil that does not result in fracture or breakage; usually the result of prolonged exposure to pressure

Fluvial deposits

Sediment deposited by rivers and
streams. Good for fossil preservation.

Lacustrine deposits

Sediment deposited in lake environments; excellent for preserving soft tissues like hair or feathers in the fossil.

Sedimentary rocks

Rocks that form when mineral and organic
particles accumulate and become either
cemented or compacted together.

Igneous Rocks

Rocks formed by cooling magma (under ground) or lava (above ground).

Metamorphic Rock

New rocks formed by the chemical or physical alteration of other rocks by extreme heat and pressure.

Coal

A combustible sedimentary rock that forms from dead vegetation (usually from wetland forests) that are deeply buried, heated, and pressurized

Limestone

A kind of sedimentary rock that is typically composed of skeletal fragments from marine organisms

Mudstone/shale

A type of fine-grained sedimentary rock that forms in slow-moving water; typical of a lake or floodplain deposit.

Sandstone

A type of sedimentary rock composed of sand-sized grains; typically forms in fast moving water such as in rivers, or in alluvial fans, lakes, deserts, beaches, or tidal flats.

Permineralization

Fossilization processes in which minerals are carried by water into the internal spaces of an organism and then solidify

Replacement

Fossilisation process in which the original bone
gradually decays and minerals fill the space that
the bone once occupied

Overburden

The earthen debris that overlays a bonebed

Long-bone alignment

The degree to which the axes of long bones (usually limb bones) share a similar orientation within a given deposit; in a fluvial context, long-bone alignment is often taken as an indicator of current direction and force

Acetabulum

Hip socket where the femur inserts; in dinosaurs, it is formed by the ilium, ischium, and pubis

Adaptation

An evolved trait that serves a specific function

Antorbital fenestra

Opening in the skull in front of the orbits; characteristic of archosaurs.

Vertebrates

A group of animals that possess vertebrae

Nares

Holes in the skull through which the nasal passages run.

Brain Case

Hollow chamber formed by multiple
skull bones that houses the brain.

Orbits

Pair of openings for the eyes.

Fenestrae

Opening in the skull that does not house a major sensory organ.

Laterotemporal fenestrae

Openings on the sides of the skull.

Supratemporal fenestrae

Openings on the top of the skull; found in diapsids

Cervical vertebrae

Vertebrae of the neck

Dorsal vertebrae

Vertebrae of the back

Sacral vertebrae

Vertebrae which are fused to form the sacrum in the pelvis

Caudal vertebrae

vertebrae of the tail

Chevrons

Bones that sit underneath the tail vertebrae- protect a large blood and nerve channel and provide support for tail muscles.

Gastralia

Small ribs positioned across a dinosaur's underbelly, underneath the ribcage.

Tetrapods

Animals that evolved from
an ancient ancestor with four feet and four
limbs.

Ilium

Upper hip bone

Ischium

Hip bone positioned closest to the tail

Pubis

Hip bone positioned in front of the ischium; forward facing in Saurischians, backwards facing in Ornithischians

Humerus

Largest bone in the upper arm, extending from the shoulder to the elbow

Radius and Ulna

Forearm bones

Carpals

Wrist bones

Metacarpals

Bones of the hand beyond the wrist bones

Phalanges

Bones of the fingers and toes

Femur

the upper leg bone (largest bone in the body)

Tibia

The shin bone, the larger of the two bones of the lower leg.

Fibula

Smaller lower leg bone

Saurischian Dinosaurs

Lizard-hipped dinosaurs are those that share an
evolutionary ancestor that had a pubis that
extended downwards and forwards, towards
the ribcage.

Ornithischian Dinosaurs

Bird-hipped dinosaurs are those
that share an evolutionary ancestor that had
both a special beak-forming bone in the upper
jaw (called the predentary) and a pubis that
extended downwards and backwards, towards
the tail.