⒈ Tips for Fighting Homework Fatigue in 4 Minutes | AIU
Order essay online cheap evolutionary physiology of animal flight Comparative vertebrate anatomy - the study of structure, of the function of structure, & of the range of variation in structure & function among vertebrates: Kingdom: Animal Phylum: Chordata Subphylum: Vertebrata Vertebrate characteristics: 1 - notochord (at least in the embryo) 2 - pharynx with pouches or slits in wall (at least in the embryo) 3 - dorsal, hollow nervous system. 4 - vertebral column Used by permission of John W. Kimball. Notochord = rod of living cells ventral to central nervous system & dorsal to alimentary canal. Fate of notochord during development: Head region - incorporated into floor of skull Trunk & tail - surrounded by cartilaginous or bony vertebrate (except in Agnathans) Adults: Fishes & amphibians - notochord persists the length of the trunk & tail but is constricted within the centrum of each vikas bharti public school holiday homework 2017 18 Reptiles, birds, & mammals - notochord almost disappears during development (e.g., remains as a pulpy nucleus in the vertebrae of mammals) Protochordates a good thesis statement for an argumentative essay notochord remains as the chief axial skeleton Agnathans - lateral neural cartilages are located on notochord lateral to the spinal cord. Pharynx - region of alimentary canal exhibiting pharyngeal pouches in embryo; pouches may open to the exterior as slits: permanent slits - adults that live in water & breathe via gills temporary slits - adults live on land Dorsal, hollow central nervous system - consists of brain & spinal cord & contains a central cavity (called the neurocoel) Among the oldest & best known = ostracoderms fishes that occurred in the late Cambrian period (see The Cambrian Explosion) through the Devonian (about 400 - 525 million years before present) had bony plates and scales (&, therefore, were easily fossilized) jawless vertebrates called 'armored fishes' Before ostracoderms? Myllokunmingia fengjiaoa (pictured below) & Haikouichthys ercaicunensis - primitive fish that have many similarities to living hagfishes and are the oldest vertebrates (530 mybf) ever found. Source: Before Vertebrates? Cathaymyrus diadexus (literally the 'Chinese eel of good fortune') is not the fossil of an eel. At just 5 cm long, but 535 m.y. old, it is the earliest known chordate (fossil shown below; for a 'reconstruction' check ). Researchers think that Cathaymyrus is a fossil relative of modern lancelets (amphioxus). Source: Non-vertebrate chordates still alive today include tunicates (or sea squirts; urochordates) & amphioxus (or branchiostoma). (cephalochordates) Phylum Chordata - established in 1874 & included organisms with: 1 - notochord. 2 - pharyngeal pouches or slits. 3 - dorsal, hollow nervous system. 4 - cells that produce the hormone thyroxine Subphylum Urochordata = tunicates Chordate 'ancestor' of vertebrates: sessile (like adult tunicates) tail evolved as adaptation in larvae to increase mobility 'higher forms' - came about by retention of tail (neoteny) Tunicate larva - also called 'sea squirt' notochord is confined to the tail notochord is lost during metamorphosis into sessile adult possess pharyngeal slits. A 530 million-year-old (although perhaps as old as 560 million years) creature, Cheungkongella ancestralisprobably a tunicate, found in the Chengjiang fauna in China's southwest Yunnan Province, might be the earliest known fossil evidence of primitive chordates (Shu, D.-G., L. Chen, J. Han, X.-L. Zhang. 2001. An early Cambrian tunicate from China. Nature 411:472 - 473.) Subphylum Cephalochordata = Amphioxus (or Branchiostoma) Vertebrate features: notochord dorsal, hollow nervous system pharyngeal gill slits 'circulatory' system - vertebrate pattern reflective essay in the mirror i see 'pumping vessels' (but no heart) Bateson added acorn worms to the phylum Chordata in 1884 because they have: 1 - a dorsal, hollow nervous system. 3 - a short diverticulum of the gut called the stomochord Present consensus = the stomochord is not homologous with the notochord and Hemichordates are placed in a separate phylum. Possible invertebrate Start Your Personal Statement the Right Way | Essay Hell 1 - annelid worms. Agnathans vs. Gnathostomes: semicircular canals agnathans have 1 or 2 gnathostomes have 3 jointed, paired lateral appendages agnathans have none gnathostomes do jaws agnathans have none gnathostomes do. 6 - Petromyzontia (lampreys) 7 - Myxinoidea (hagfishes) Ostracoderms (Osteostraci, Anaspida, Heterostraci, & Coelolepid): 1 - extinct Paleozoic (Cambrian to Devonian) jawless fish with an external skeleton of bone ('bony armor') 2 - oldest known vertebrates 3 - Tips for Fighting Homework Fatigue in 4 Minutes | AIU had flattened appearance (some may have been bottom-dwellers) Cyclostomes (Petromyzontia & Myxinoidea): Lampreys - parasitic with horny, rasping teeth (see drawing at right) 2 - probably related to modern bony fishes. 3 - small (less than 20 cm long) with large eyes. 4 - Acanthodians most likely died out because of the rapidly increasing number of ray-finned fishes and sharks during the Permian. The relationships of acanthodians to other vertebrates has been the subject of considerable debate. Early researchers considered them to be most closely related to the ray-finned fishes, but most scientists during the mid-20th Century considered acanthodians to have a closer affinity to the sharks. Opinion has now generally swung back in favor of a closer relationship with ray-fins, but this is far from universally accepted. Class Placodermii: 1 - Silurian (about 420 million years before present) 2 thank you for your support thesis committee probably off the main line of vertebrate evolution. 3 Doctoral Dissertation Writing Help by Ph.D. Writer many had bony dermal shields. 4 - some were probably predators (with large, sharp 'tooth plates') Placoderms were armored pa divorce forms printable fishes that first appeared about 420 million years ago (MYA) during the Silurian Period. They had diversified dramatically by the beginning of the Devonian and came to dominate most marine and freshwater ecosystems before becoming extinct at the end of that period (355 MYA). About 200 genera how to start master thesis defense presentation placoderms have been discovered, with most of these occurring during the Devonian radiations. The rapid evolution and diversity of placoderms have made them useful in dating Devonian rocks. Placoderms (= plated skin) were named for their heavy armor of dermal bone, which formed large shields on the head and thorax. The rest of their bodies was covered with small bony scales or was without dental armor. The head and trunk shields of most placoderms were articulated by bony joints. This joint apparently allowed the forward Science Topics for children - Primary Homework Help for Kids of the skull to tilt up, increasing the gape. Placoderms lacked teeth, but biting or grinding structures are often be found in the dermal bones Reading Support and Homework | Bulk, Wholesale | BookPal their mouths. Placoderms evolved into a variety of body forms in a relatively short gadsden county recent arrests. Many were torpedo-shaped, but there were notable expections, including the flatten Phyllolepida and the bottom feeding Antiarchi. Most placoderms were less than 30 cm (2 feet) in length, but some members of the dinichthyids (= terrible fish) reached or exceeded 6 m (20 ft), making them the first giants of the vertebrate lineage. Class Chondrichthyes - cartilaginous fishes 1 - ancestors had bony skeletons so cartilaginous skeleton is specialized. 2 - pelvic fins of males are modified as claspers. 4 - numerous today but more abundant in the past Subclass Elasmobranchii - most common cartilaginous fishes O. Cladoselachii - primitive sharks (300-400 mybp) O. Selachii - 'modern' sharks. O. Batoidea - Tips for Fighting Homework Fatigue in 4 Minutes | AIU & skates Elasmobranchs: 1 - 1st pharyngeal slit modified as a spiracle. 2 Cbbc Homework Help - buywritebestessayw.rocks naked gill slits (no operculum) 3 - mouth located ventrally Subclass Holocephali O. Chimaeriformes (photo & drawing) marine gill slits have a fleshy operculum & the spiracle is closed few scales common ancestor with sharks but an Tips for Fighting Homework Fatigue in 4 Minutes | AIU line. Class Osteichthyes - bony fishes 1 - skeleton is partly or chiefly bone. 2 - gill slits are covered by a bony operculum. 3 - skin has scales with, typically, little bone. 4 - most have a swim bladder. 5 - ray-finned or lobe-finned Subclass Actinopterygii - ray-fins Superorder Chondrostei most primitive ray-fins chiefly Paleozoic (300-400 mybp) include present-day Sturgeons & Paddlefish (below) Superorder Neopterygii Order Semionotiformes dominant Mesozoic fishes possess ganoid scales two extant genera: Lepidosteus - predatory; includes present-day gars Amia - includes present-day bowfins (or dogfish) Division Teleostei - modern ray-finned fishes recent bony fishes 95% of all living fish about 40 living orders well-ossified skeleton Lord of the Flies Map Project | The Daring English Teacher & ctenoid scales (flexible & overlapping) pelvic fins often located far forward no spiracle 1 = operculum, 2 = dorsal fin, 3 = caudal peduncle (The narrow section of a fish's body directly anterior to the insertion of the tail but before the mid-body.), 4 = caudal fin or "tail", 5 = anal fins, 6 = pelvic fins, & 7 = pectoral fins (Source: ) Subclass Sarcopterygii - lobe-finned fishes O. Crossopterygii Doctoral Dissertation Assistance University Of Michigan chiefly Paleozoic except Latimeria 1 - resemble early amphibians. 2 - skeleton of fin lobe corresponds closely to proximal skeletal elements of early tetrapod limbs. Used with permission of John Kimball 3 - skull similar to that of early amphibians. 4 - had swim bladders that may have been used as lungs O. Dipnoi - lungfish (3 living genera; Africa, Australia, & South America) African & South American species have inefficient gills & will Tips for Fighting Homework Fatigue in 4 Minutes | AIU if held under water Australian species ( For Students: Goyal assignment original custom papers! spp.) relies on gills unless oxygen content of water is too low. Class Amphibia Oldest known = subclass Labyrinthodontia Fish-like features: 1- small bony scales in the skin. 2- fin-rays in the tail (for swimming) 3- a skull similar to that of some Crossopterygians. 4- a sensory canal system (like the lateral line system) that indicates a primarily aquatic existence. Labyrinthodonts are distinguished by deeply folded structure of enamel and dentine layers in the teeth, that look like an intricate labyrinth in the cross section, hence the name of this group. Labyrinthodonts were probably similar to fishes in their mode of living. Labyrinthodonts, like fishes and most modern amphibians, laid eggs in the water, where their larvae developed into mature animals. All labyrinthodonts had special sense North schuylkill homework helpline | Thematic essay in the skin, that formed a system for perception of water fluctuations. Moreover, some of them possessed well developed gills. In contrast, many labyrinthodonts seemingly had primitive lungs. They could breath atmospheric air, that was a great advantage for residents of warm shoals with low oxygen levels in the water. The air was inflated into the lungs by contractions of a special throat sac. Primitive members of all labyrinthodont groups were probably true water predators, and only advanced forms that arose independently in different groups and times, gained an amphibious, Tips for Fighting Homework Fatigue in 4 Minutes | AIU mode of living. Mature individuals of advanced labyrinthodonts could live on land, feeding mainly on insects and other small invertebrates. Well ossified robust skeletons in some Late Carboniferous and Early Permian labyrinthodonts prove their adaptation to the terrestrial mode of life. It suggests that amphibians had successfully 'organized' actual terrestrial assemblages prior to the wide expansion of reptiles. The most diverse group of the labyrinthodonts was the batrachomorphs postion paper writing service to a frog'). Conducting research literature reviews these animals looked more like crocodiles, they most probably gave rise to the order Anura, the amphibians without tails, which include, in particular, the modern frogs. Batrachomorphs appeared in the Late Devonian, but they had worldwide distribution in the continental shallow basins of the Permian (Platyoposaurus, Melosaurus) and Triassic Periods (Thoosuchus, Benthosuchus, Eryosuchus). Some batrachomorphs existed until the end of the Cretaceous. Subclass Lepospondyli ancestry uncertain due to lack of fossil evidence probably on a 'side branch' of vertebrate evolution Subclass Lissamphibia - modern amphibians O. Anura - frogs & toads O. Urodela - tailed amphibians O. Gymnophiona (apodans) - wormlike, burrowing amphibians. Modern amphibian characteristics: 1 - aquatic larval stage with external gills. 2 - middle ear cavity with ear ossicle (columella) 3 - no bony scales (except apodans) 3 Tips for Fighting Homework Fatigue in 4 Minutes | AIU large, yolk-laden, shell-covered eggs laid on land Stem reptiles = Cotylosaurs (about 300 mybp) Reptile Subclasses: 1 - Anapsida O. Cotylosauria - stem reptiles O. Chelonia - turtles & tortoises unchanged Dissertation Service In Malaysia Cheapest - Dissertation about 175 million years identified by bony dermal plates to which ribs & trunk vertebrae school writing paper fused 2 - Lepidosauria O. Rhynchocephalia (Sphenodonta) - only living representative is the Tuatara O. Squamata - lizards, geckos, & snakes 3 - Archosauria O. Thecodontia - stem archosaurs O. Pterosauria (check case study research design and methods 4th ed short video & this one) O. Saurischia - 2 major groups: sauropods & theropods (check this short video) Tips for Fighting Homework Fatigue in 4 Minutes | AIU. Ornithischia (like Iguanodon) O. Crocodilia 4 - Euryapsida - marine Tips for Fighting Homework Fatigue in 4 Minutes | AIU, includes the plesiosaurs (check this short video) & ichthyosaurs (check this short video) Representative ichthyosaurs Source: 5 - Synapsida O. Pelycosauria - first stage in evolution to mammals O. Therapsida. Saurischia (sawr-RIS-kee-ah) & Ornithischia are the two orders of dinosaurs, with the division based on the shape of the pelvic bone. The saurischian pubis (left) juts forward, and its ischium points backward. The ornithischian pubis and ischium (right) both point backward. The ornithischians were all herbivorous, and included some of the most interesting-looking dinosaurs. Ornithischian dinosaurs include three suborders: Ornithopoda, Can you please clarify the definition of a sampling error and Thyreophora. The famous carnivorous dinosaurs were from the saurischian order, as were the largest herbivorous dinosaurs. The saurischian dinosaurs include two suborders: Theropoda and Sauropodomorpha. The first vertebrates to evolve true flight were the pterosaursflying archosaurian reptiles. After Homework Help Maths Ks2 - cidso.org discovery of pterosaur fossils in the 18th century, it was thought that pterosaurs were a failed experiment in flight; a humorous mishap; or that they were simply gliders, too weak to fly. More recent studies have revealed that pterosaurs were definitely proficient flyers, and were no evolutionary failure; as a group they lasted about 140 million years (about as long as birds have)! Pterosaurs are thought to be derived from a bipedal, cursorial (running) archosaur in the late Triassic period (about 225 million years ago). No other phylogenetic hypothesis has withstood examination; however, the early history of pterosaurs is not yet fully understood because of their poor fossil record in the Triassic period. We can infer that the origin of flight in pterosaurs fits the "ground up" evolutionary scenario, supported by the fact that pterosaurs had no evident arboreal adaptations. The pterosaur wing was supported by an elongated fourth digit (imagine having a "pinky finger" several feet long, and using that to fly!). Pterosaurs had other morphological adaptations for Tips for Fighting Homework Fatigue in 4 Minutes | AIU as a keeled sternum for the attachment of flight muscles, a short and stout humerus (the first arm bone), and hollow but strong limb and skull bones. Pterosaurs also had modified scales that were wing-supporting fibers, and that possibly formed hairlike structures to provide insulation -- bird feathers are analogous to the wing fibers of pterosaurs, and both are thought to possibly have been evolved originally for the primary purpose of thermoregulation (which implies, but does not prove, that both pterosaurs and the earliest birds were endothermic). Early pterosaurs (such as Dimorphodon) had long tails that assisted balance, but later pterosaurs had no tails, and may have been more adept flyers. The most derived pterosaurs, such as Pteranodon and Quetzalcoatlus, were so large that soaring was the only feasible option; these were the largest flyers ever to cast a shadow on the Earth's surface. Reptile subclasses - classified in part according to presence or absence of temporal openings Synapsid type = mammal-like reptiles Anapsid type = stem reptiles & turtles Diapsid type = rhynchocephalians, lizards, & snakes Euryapsid type = extinct plesiosaurs. Temporal fenestration has long been used to classify amniotes. Taxa such as Anapsida, Diapsida, Euryapsida, and Synapsida were named after their Online Thesis Writing Service - Avail Our Services Anytime of temporal fenestration. Temporal fenestra are large holes in the Ptlls Level 4 Essay - 1405 Words | Bartleby of the skull. The function of these holes has long been debated. Many believe that they allow muscles to expand and to lengthen. The resulting greater bulk essay on importance of science in hindi language muscles results in a stronger jaw musculature, and the longer muscle fibers allow an increase in the gape. 2 - lost several dinosaur characteristics (e.g., long tail & teeth) but retained others (e.g., claws, scales, diapsid skull, single occipital condyle &, perhaps, feathers) (see AMNH website purpose of oral presentation ABC News website) Subclass Archaeornithes Genera: Archaeopteryx & Archaeornis Characteristics: 1 - solid bones. 2 - weakly developed keel &, probably, weakly developed flight muscles Subclass Neornithes Superorder Odontognathae extinct many features of modern birds (e.g., hollow bones & short tail) Superorder Paleognathae ratites small wings but powerful leg muscles Superorder Neognathae - birds adapted for sustained flight Modifications to reduce weight include: loss of some bones pneumatic bones reduced tail loss of teeth loss of urinary bladder Class Mammalia Characteristics: 1 - hair 2 - mammary glands 3 - 3 middle ear bones 4 - muscular diaphragm 5 - sweat glands 6 - marrow within bones 7 - 2 sets of teeth 8 - biconcave, enucleate red blood cells 9 Pay For Dissertation Accounting - buyworkpaperessay.org well-developed cerebral cortex. Subclass Prototheria - egg-laying mammals O. Monotremata - platypus + 2 spiny anteaters 1 - lay eggs 2 - testes within the abdominal cavity 3 - no pinna 4 - no corpus callosum 5 - less stable body temperature Subclass Theria Infraclass Metatheria O. Marsupialia - pouched mammals; young born alive, but at a very immature stage Infraclass Eutheria - placental mammals.