#pale

• Arietites — A fossil genus of ammonites (extinct marine cephalopod mollusks) from the Early Jurassic period, characterized by a large, planospiral shell with prominent transverse ribs and a distinct central keel; the name suggests the resemblance of the coiled shell to the horns of the Egyptian god Ammon or a ram, serving as a critical index fossil for dating geological strata of the Sinemurian stage.
• Aristogenesis — An idealistic evolutionary theory, formulated by paleontologist Henry Fairfield Osborn, stating that the evolution of living organisms is determined by the gradual emergence of new, superior adaptive genes and characters directly from the internal potential of the germ plasm, independent of natural selection or the direct influence of the environment. In modern biology, the term is considered historical, describing a predetermined biological improvement mechanism.
• Artinskian — An age or stage in the Cisuralian epoch of the Permian period, geochronologically dated between approximately 290 and 283 million years ago; relating to this stage. In theoretical geology, the term describes an era marked by major climate shifts and massive marine sediment depositions, originally defined in the Ural Mountains region of Russia.
• Long-tailed wild ginger — The scientific name of the British Columbia wild ginger or long-tailed wild ginger, a perennial plant species in the Aristolochiaceae family, native to the moist, forested regions of western North America. It is structurally distinguished by its unique reddish-brown flowers, whose sepals extend into very long, narrow tail-like lobes.
• Aspidoceras — An extinct genus of ammonites (coiled marine cephalopod mollusks) in the family Aspidoceratidae, which lived during the Late Jurassic and Early Cretaceous periods. Fossils of this genus are recognized by their robust, evolute shell, characterized by distinctive rows of nodes or spines arranged on the flanks, used by paleontologists as index fossils for dating marine geological strata.
• Astaco- — A scientific combining form (prefixoid) extracted from the Greek language (from 'astakos'), used in rare scientific, zoological, and paleontological terminology to refer to crayfish, decapod crustaceans of the Astacidae family, or to describe anatomical and fossil structures belonging to or closely related to this group of aquatic organisms.
• Astacoid — Resembling a crayfish or the species of the Astacus genus in form, structure, or general appearance; a morphological adjective used to describe fossil specimens, crustacean larvae, or external anatomical characters (such as the carapace or claws) reminiscent of the river crayfish's structural configuration.
• Fossilized crayfish — The fossilized remnant, petrified imprint, or petrographic cast of a prehistoric crayfish or a part of the exoskeleton of a decapod crustacean from the Astacidae family; these structural fossil formations are used in stratigraphical geology as biofacial indicators for reconstructing ancient freshwater aquatic environments.
• Asteroxylon — A genus of primitive fossil plants (Asteroxylon) from the Lycopodiopsida class, characteristic of the Early Devonian, discovered in the famous Rhynie chert deposits (Scotland); they were ancient terrestrial plants with dichotomously branched stems covered with scale-like leaf-like outgrowths (enations) and featuring a star-shaped central cylinder (actinostele) visible in cross-section.
• Aulacoceras — An extinct genus of dibranchiate cephalopods from the order Belemnoidea, characteristic of the Triassic period. This ancient marine organism was notable for an elongated, conical, calcareous internal shell marked on its outer surface by prominent longitudinal grooves.
• Australopithecine — An extinct homnid primate belonging to the genus Australopithecus, inhabiting Africa approximately 4 to 2 million years ago. Characterized by primitive bipedalism, a small cranial capacity, and human-like dentition, it represents a crucial link in the evolutionary lineage of hominins.
• Australopithecines — A generic term utilized in the plural to designate a broad group of early hominins belonging to the subtribe Australopithecina, including the genera Australopithecus and Paranthropus. As a plural adjective, it describes anatomical traits, cranial structures, or primitive bipedal locomotion specific to these primates.
• Australopithecus — A localized graphical and phonetic adaptation of the scientific Latin name 'Australopithecus', utilized as a synonym in simplified datasets or science popularization texts to designate the extinct bipedal hominin from prehistoric Africa.
• Autunian — A transitional geological stage located at the base of the Lower Permian (or late Upper Carboniferous), defined by successions of oil shales rich in fossil flora (Callipteris conferta) historically researched in the basin of Autun, France; as an adjective, it refers to the formations, rocks, or fauna specific to this time interval.
• Auversian — A regional subdivision or transitional geological stage of the Middle Eocene within the Paleogene period, defined by the fossiliferous sand deposits researched in Auvers-sur-Oise, Paris Basin (France); as an adjective, it denotes the sedimentary formations or marine fauna characteristic of this epoch.
• Aviform — Having the shape of a bird, structurally resembling a bird, or presenting exterior morphological characteristics specific to the avian class; a term used in comparative anatomy, paleontology (for describing certain dinosaur fossils), and in design or art to qualify objects or structures mimicking a bird's profile, silhouette, or details.
• Avrutd — An archaic hypercorrect graphic form, corrupted, or paleographic transcription error found in medieval manuscripts for names in the 'Abrud / Avrud' family. It represents a parasitic hybrid consonantal insertion (the 'td' group), specific to the orthographic hesitations of copyists in old chancelleries who tried to render local phonetisms through foreign spellings.
• Avvad — A rare graphic form, archaic variant, or onomastic derivative of Semitic / biblical origin associated with roots in the 'Abbad / Abba' family, encountered sporadically in old translations of Near Eastern religious texts or as an exotic proper name in medieval charters. It may reflect a special phonetic adaptation or a transcription error of callophonic names borne in Near Eastern ecclesiastical circles.
• Baculite — A member of the extinct genus Baculites, representing an Upper Cretaceous ammonite characterized by an almost completely straight, elongated, rod-shaped calcareous shell, unlike classic spiraled ammonites. Geologically, baculite fossils are utilized as highly important index fossils for dating marine sedimentary layers and reconstructing prehistoric ecosystems.