Glossary S
Sacral
1. Located in or relating to the sacrum. 2. One of the bones of the sacrum. n., the part of the backbone that attaches the pelvis to the spine, usually formed by the fusion of two or more vertebrae --sacral adj.
Sacral ribs
Special strong ribs that connect the vertebral column to the pelvis
Sacrum
The group of fused vertebrae forming the attachmant of the pelvis to the spinal column. n., the part of the backbone that attaches the pelvis to the spine, usually formed by the fusion of two or more vertebrae --sacral adj.
Saggital
1. Relating to the imageniary midline of the body dividing it vertically into two symmetrical halves. 2. Relating to the line of function of the two halves of the skull.
Saurian or Sauroid
1. A lizard. 2. Relating to or resembling a lizard.
Saurischian
One major grouping of the dinosaurs (based on the hip structure) in which the pubis is long and points forward and downward from the hipsocket; includes the carnivorous theropods and the herbivorous sauropodomorphs.
Saurolophine
Refering to hadrosaurids with slender spikes on head
Sauropodomorphs
Large herbivorous saurischian dinosaurs including the prosauropods and sauropods
Scansorial
Able to climb; having the behavior pattern of climbing.
Scapula
The shoulder blade
Scapulocoracoid
Bone formed by the fusion of the scapula and coracoid
Scavenger
An animal that feeds on the flesh of dead animals, but that typically eats the flesh of prey which has died naturally or has been killed by others, as opposed to actively hunting and killing live prey itself.
Sclerotic ossicles
Bones found in the sclera or \"white\" of the eye
Sclerotic plate
Bone on the eyeball that provides a strong attachment point for muscles. Typical of animals that rely heavily on vision
Sclerotic ring
Ring of sclerotic plates
Scute
A bony plate or knob under the skin.
Secondary bone
Bone that is formed during internal reconstruction after preexisting bone tissue has been disolved and reconstituted. Compare Primary bone.
Sedimentary rocks
Rocks that have formed from sediments such as sands and clays
Sedimentology
1. The study of sediments and sedimentary rocks. 2. The sediments found in a particular area.
Sediments
Fragments of organic or inorganic material that are carried or deposid by wind, water, or ice, and that then are accumulated in unconsolidated layers on the surface of the earth.
Selection
The principle that organisms possessing a certain hereditary characteristic will tend to reproduce at a more succesful rate than others of the same population lacking this feature, and will thus become a higher percentage of the population in successive generations.
Septum [plural] Septa
In anatomy, a dividing wall or partition.
Serrated
With a notched edge like cutting edge of a saw.
Sexual behaviour
All activity that promotes or leads to reproduction.
Sexual dimorphism
The fact of having, distinct male and female forms of the same species, especially visible differnces in coloration, body shape, size, and so on.
Shales
A rock type composed mainly of clay that splits into thin wafers.
Shatter cone
Striated conical fracture surfaces produced by meteorite impact into fine-grained brittle rocks such as limestone.
Shield
Any of several extensive regions where ancient Precambrian crystalline rocks are exposed at the Earth’s surface.
Shock metamorphism
The production of irreversible chemical or physical changes in rocks by a shock wave generated by impact, or detonation of high-explosive or nuclear devices.
Siderophile elements
Literally, “iron-loving” elements, such as iridium, osmium, platinum, and palladium, that, in chemically segregated asteroids and planets, are found in the metal-rich interiors. Consequently, these elements are extremely rare on Earth’s surface.
Silica
One of several abundant minerals in the Earth\'s crust based on the element silicon.
Silt
Grains or finely broken pieces of rock that slowly settle out of water
Sinuses
Spaces whitin the body
Sister group / Sister clade
One of the two corresponding branches in an evolutionary tree or diagram, resulting from the splitting of a single line of descent; one of two groups more closely related to each other than any other group under consideration. Also, Sister clade.
Sister species
One of a pair of species arising from a single event of specification; a species that is the closest relative of another species.
Skeletogenesis
The growth or formation of the skeleton.
Social behaviour
Any association of two or more members of a given species for a period of time, in circumstances other than the usual female-male interaction for reproduction; e.g., nesting, herding, hunting in packs.
Solar panels
Flat surfaces that are able to absorb the warmth of the sun
Spatulate
In anatomy, shaped like a spoon or spatula
Specialized / Specialization
Of a character or feature, greatly modified from the original ancestral state, in response to specific environmental conditions. Thus, specialization.
Speciation
The formation of new species; the process by which a distinct population develops as a result of evolutionary processes and forces.
Species
1. The fundamental level of classification used in the systematic indentification of living things; the catagory that provides, along with the next higher level of genus, the scientific name of a plant or animal.
2. A distinct group of organisms that is so classified by any of various standards, typically on the basis of having a common ancestry and the ability to reproduce freely whitin the group, but not outside it.
Sphenoid / Sphenoidal
A large, wedge-shaped bone at the basis of the skull. Thus, sphenoidal.
Splenial bone
Mandible bone
Squamosal
A bone at the rear side of the skull, associated with the suspension of the jaw from the skull.
Squamosal bone
Skull bone
Squamous / Squamatic
Covered with or composed of scales; scaly. Also Squamatic
Stabilizing selection
A process of natural selection in which genetic variation is selected against, resulting in a population from which peripheral variants are eliminated, thus maintaining the existing state of adaption. Compare disruptive selection.
Stem-based / Stem-difined
Describing a taxonomic group that is defined as all those enities that share a more recent common ancestor with one group than another; e.g., Saurischia includes birds and all those dinosaurs that are closer to birds than they are to Triceratops. Also, Stem-difined. Compare Node-based
Stereoscopic
Relating to an ability to perceive a three-dimensional image
Sternal
Relating to or involving the chest (breastbone).
Sternal plate
One of the two halves of the sternum, or chest. These bones are usually imbedded in cartilage and are sometimes poorly ossified. In dinosaurs, they generally do not articulate directly with the shoulder girdle (at the coracoids) but \"float free\" in the chest cartilage. They serve to anchor the tips of the thoracic ribs and the front of the abdominal ribcage, and they act as braces and spacers for the lower shoulder bones (coracoids). In flying birds, the sternal plates are fused solidly together into a relatively huge, keeled breastbone that serves to anchor the pectoral muscles that work the wings
Sternum
The long, flat bone at the center of the chest, the breastbone
A dense, high-pressure phase of quartz that has so far been identified only in shock-metamorphosed quartz‑bearing rocks from meteorite impact craters.
Stratigraphy
The study and description of the manner in which rocks or other material from strata (see below) on the surface of the earth.
Stratum [plural] Strata
A distinct, observable segment of rock or other material forming a uniform or similar layer on the surface of the earth, visibly separated from other layers above and below it.
Stromatolites
Banded rocks that were made by blue-green algae; abundant in the Precambrian in particular.
Subfamily
A classification of organisms that is more precise than a family but more inclusive than a genus; a subdivision of a family.
Suborder
A catagory smaller than Order but bigger than Infraorder; used in the classification of animals
Subspecies
1. The taxonomic rank immediately below a species; a subdivision of a species. 2. A distinct group of organisms so classified, typically isolated geographically from other populations of the same species but potentionally able to interbreed with them; also often displaying certain minor differences in form or appearance.
Subtaxon [plural] Subtaxa
A subdivision of a taxon.
Suite
A group or array of characteristics associated with a given organism or species.
Sulcus
Grove
Sungenus [plural] Subgenera
A classification of organisms that is more precise than a genus but more inclusive than a species; a subdivision of a genus.
Super-
A prefix meaning \"above\" or \"greater\".
Supercontinent
An earlier and larger land mass composed of currently existing continents.
Superior temporal fenestra
Upper temporal fenestra in diapsids
Supernova
The last phase in the life of certain type of star, when it annihilates itselfin an enormous explosion.
Superorder
A catagory bigger than Order but smaller than Class, used in the classification of animals
Supra-
In anatomy, a prefix meaning \"over\" or \"above\"; e.g., the supracranial region is the upper surface of the cranium; a supratemporal feature is located above the temporal bone.
Surangular bone
Mandible bone
Suture
A line where bones meet
Symphysis
1. In anatomy, a fushion point between two structures. 2. Specifically a joint between two bones in which the joint cavity is filled by fibrous cartilage.
Symplesiomorph / Symplesiomorphic / Symplesiomorphy
A plesiomorph (character present in an ancestral form, and also in descendant forms) that is shared by two ore more groups, thus indicating common ancestry for these groups. Thus, Symplesiomorphic, Symplesiomorphy.
Syn-
A prefix meaning \"associated; together\" or \"fused; united\".
Synapomorph / Synapomorphic / Synapomorphy
A apomorph (character derived from, but no longer the same as, an earlier character) that is shared by two or more groups. Thus, Synapomorphic, Synapomorphy
Synapsid
One of the Synapsida, a group of amniotes including mammals and their relatives closer to them than to reptiles; identified by a single opening in the skull behind the orbit (eye socket).
Synchronicity / Synchrony / Synchronousness
The fact of two (ore more) events or conditions occuring at the same time. Also, synchrony, synchronousness.
Syntype
Each specimen of a type series from which neither a holotype nor a lectotype has been designated.
Systematics
The branch of science that involves classifying and naming organisms according to certain established, consistent principles.