2 Test Study Guide I. Phylum Cnidaria General Characteristics: Radial symmetry with 2 body forms o Polyp feeding orientation of the cnidarians, anchored to the substrate, mouth and tentacles point upward o Medusa feeding orientation of the cnidarians, free floating, mouth and tentacles point downward Tissues 2 layers (no totipotent cells) o Gastrodermis digestive layer o Epidermis o Mesoglea Cnidoblasts nematocysts stinging cells in the tentacles, used to kill or stun prey Mostly marine Many colonial, some solitary Many attached, some free living Colored, transparent, colorless Incomplete digestive system; mouth, digestive cavity (enteron), tentacles No respiratory, excretory, nervous (partial), muscular (mesentaries only; folds in the organisms body wall, increases the surface area to aid in absorption and digestion), circulatory system, or anus Calcareous or organic skeleton may be present Evolutionary Model: Ciliated, colonial protozoan ancestor * Protomedusa earliest body form; protomedusa instead of polyps o Feeding and locomotion o Protective layer o Circulation and reproduction o Motion o Specialization o Blind gut Polyploid line o Sensory and food o Reorientation o Radial symmetry o Two tissue layers with middle region Class hydrozoa emphasizes polyp Class scyphozoa emphasizes medusa
Class Anthozoa only polyps can divide; reproduce sexually Classification: Class Hydrozoa PC to recent, radial symmetry. Most species have both medusoid and polyploid stages. Coelenteron not partitioned; mesoglea gelatinous, noncellular. Solitary or colonial, mostly marine, pelagic, sessile benthos o Order hydroida PC to recent. Polyploid stage well developed, colonial or solitary. Marine and fresh water; pelagic, sessile benthos. o Order milleporina Late cretaceous to recent. Polyploid colony with massive to encrusting calcareous skeleton with pores through which polyps protrude. Medusoid generation reduced. Marine, predominantly sessile benthos o Order stylasterina late cretaceous to recent. Massive to encrusting skeletons with pores for polyps. Non-medusoid. Marine, sessile benthos o Order siphonophora ordivician to recent. Colonial. Polyps with medusa attached to stem or disk. Supported by swimming bell or float. Marine, pelagic. Rare as fossils. Class scyphozoa Precambrian to recent. Solitary. Coelenteron divided in some by mesentaries. Radial symmetry. Polyp much reduced, highly modified or lost. Mesogloea cellular. Entirely marine, predominately pelagic. o Subclass scyphomedusa Precambrian? Cambrian? Late jurassic to recent. True jelly fish. Marine, predominately pelagic. Rare as fossils. o Subclass conulata middle cambrian to early triassic. Skeleton of chitin and calcium phosphate; form, elongate pyramidal. Attached by apex of pyramid or free. Traces of tentacles preserved as well as evidence of tentacular muscle attachments. Probably marine, sessile or planktonic. Class Anthozoa
Class Anthozoa Order zooantharia (colonial anemones) Order Actinaria (solitary anemones) Order Rugosa
Range
Skeleton
S/C All colonial
Septa None
Tabulae None
Precambrian Organic to recent
Mural Pores None
Edge Zone None
Precambrian Organic to recent
Solitary
None
None
none
None
Middle ordivician to early triassic
Low mg calcite
Mostly solitary, some colonial
2,2,4,4,4,.. Counter, cardinal, alas, counter lateral,
Yes
No
Not usually
Order Tabulata (have millepores) Order Scleratina (most probable ancestor of these corals colonial soft bodied forms
Ordivician to permian
Low mg calcite
All colonial
secondary 0,6,12 Microscopic
Yes
Yes
No, they don't need it Yes
Late triassic to recent
CaCO3 but mineral aragonite
Mostly colonial, some solitary
6,6,12,24,48 Yes (Primary, secondary..)
No
II. Phylum Bryzoa General characteristics: Small, colonial (microscopic) Aquatic Complete digestive system Lophophore feeding structure which looks like feathers surrounding the mouth Muscles Ancestors phoronid worm Relationship to Brachiopods: Similarities o Larval development o Form = trachophore o Sense organ Differences o Bryo colonial, brachio solitary o Bryo tubules or boxes, brachio valves o Size; bryo microscopic, brachio megascopic o Reproduction; bryo sexual and asexual, brachio sexual only o Composition; bryo organic or calcareous low mg, brachio phosphate or calcareous low mg Development differences o Ancestrula develops first o Protoecium
o o
Additional individuals are zooecia (autopores Lophophore
Development stages of colony (zoarium): Larva Ancestrula develops first Protoecium Additional individuals are zooecia forming zoarium Specialized Individuals: Modern bryozoans o Protective Avicularia bird beak ones protects against predators Vibricularia whips that vibrate, keep sediment off body o Ovicells responsible for secreting eggs/sperm Fossil structures o Mesopores small holes o Acanthopores small spikes (solid) (either protective or supportive) Evolutionary trends: Ancestors, ordivician beginnings to present Most primitive forms organic Advanced boxes; encrusting, ramose, arborescent, fenestrate Shape: tubes to boxes Calcification: organic to calcite Environment and morphology: Back reef lagoon arborescent Reef crest encrusting, massive high energy water Fore reef fenestrate Classification: Class phylactolaemata cretaceous to recent. Freshwater only. Only 1 fossil genus recognized. Horseshoe shaped lophophore, lip over mouth, chitinous or gelatinous skeleton Class stenolaemata early ordivician to recent. Abundant paleozoic and mesozoic bryozoans with calcified, inflexible body walls, conical or tubular zooids; body walls with one cellular layer = epidermis; simple, circular orifice; tentacles circle mouth
Class gymnolaemata late ordivician to recent. Unclacified, isolated encrusters to calcified colonies. Freshwater and marine. Box like zooecia with 2 layered walls having pores, operculum. Specialized zooids include avicularia, kenozooids, brood chambers o Order ctenostomata late ordivician to recent. "Primitive". Unclacified, flexible tubes, rare opercula, encrusting, boring, or erect tubes budding off stolon o Order cyclostomata (tubuliporata) early ordivician to recent. May have free wall and variable growth forms. Bundles or groups of calcareous tubes that extend vertically upward before turning outward. Have ovicells, simple apertures. Peak in cretaceous. o Order trepostomata early ordivician to triassic with a peak in the ordivician and silurian. Massive, encrusting or frondose calcareous zoaria; some specialized zooecia. Diaphragms with mature and immature regions. Early paleozoic reef builders o Order cryptostomata early ordivician to triassic. Delicate reticulate or pinnate colonies. Zooidal apertures ON FRONT SIDE ONLY. Zooids short. Order may be derived from trepostomata. Peak in late paleozoic. o Order cheilostomata late Jurassic to recent. Calcified with flexible frontal wall, box short, like zooecia, small apertures with elevated rim (orifice wall = peristome) and opercula in most genera. Erect, rigid, flexible, jointed, free living. Specialized cells present. Important in post cretaceous rocks. III. Phylum Brachiopoda Introduction: Diversity = biostratigraphic tool General Characteristics: Marine and brackish water, not in fresh water or on land 2 valves dorsal and ventral valve Bilateral symmetry Lophophore = brachia Life habits o Cemented o Floating on sediment o Attached by pedicle o Lungula free lining o "swimmers" Soft Parts: Mantle lines inside and forms shell. Secretes and repairs shell. Digestive system complete/incomplete Open circulatory system pallial line (between mantle and shell) Nerves
Pedicle exclusive for brachipods Muscles o Adductors muscles that close and/or hold valves together. May leave attachment scars on interior surface of valve o Diductors muscles that open valves. Insert on floor of pedicle valve and along or adjacent to hinge line on brachial valve. Attachments may show as scars on inner surfaces of valves o Linguliformea and craniformea vs rhynchonelloformea Lophophore appendage extending anteriorly from mouth and consisting of a lobed disk or a pair of coiled arms (brachia). The arms or lobes attach on either side of the mouth and bear on their edges slender, ciliated threads (cirri) Hard Parts: Diverse Shell structure and composition o Chitinophosphatic o Calcareous (low Mg) Impunctate earliest, no holes Pseudopunctate solid spikes Punctate holes Shell nomenclature o Beak posterior end, pointed extremity of valve adjacent to or posterior to the hinge line and in midline of valve o Interarea plane or curved surface between beak and hinge line on either valve. Generally distinguished by a sharp break in angle from the remainder of the valve and by the absence of costae, plication or coarse growth lines o Delthyrium opening in pedicle valve adjacent to hinge line. Serves for passage of pedicle o Notothyrium opening in brachial valve adjacent to and outside the hinge line. Forms part of the opening for the pedicle o Chilidial plate plate at side of the opening (notothyrium) in the brachial valve for pedicle o Deltidial plates plate on either side of pedicle opening (delthyrium) in pedicle valve that constricts opening or even, with its mate from opposite side, closes it off completely Evolutionary Trends: Lophophore supports o Brachiophore-cardinal process, median septum o Loop-crura and jugum o Spirallum crura and spire (atrypid, athryid, spireferid)
Classifications: Class Lingulata all brachipods with phosphatic shells, open, U shaped, digestive tract with anus, musculature with 1 or 2 u bonal muscles, 3 or 4 pairs of oblique muscles, paired central muscles and dermal muscles in anterior body wall for opening shell. Cambrian to recent o Order lingulida CaPO4, spatulate valves with pedicle emerging posterior between both valves. Cambrian to recent o Order Actrotretida shell ventrally biconvex with conical to sub conical ventral valves and dorsal valve with apical pedicle foramen commonly with pseudointerarea. Cambrian to devonian Class paterinata larval shell pustulose; strophic cardinal margins, fused mantle lobes, paired dorsal adductor and diductor muscles, notothyrium and delthyrium. Cambrian to ordivician o Order Paterinida strophic shells with variably developed inter-areas with notothyrium and delthyrium. Cambrian to ordivician Class Obolellata primitive articulation, CaCO3. Shell biconvex, impunctate, well defined interareas, articulatory structures variably developed. Low-middle Cambrian o Order Obolellida oval, biconvex, calcareous valves with primitive articulation. Lowmiddle cambrian Class Strophomenata planoconvex shells or convexo-concave. Shell consisting of bladed (prismatic) and lamellar laths of calcium carbonate: impunctate, pseudopunctate, and punctate; variable shell outline, plano-weakly convexo concave; variable interarea and pedicle openings that may be sealed in adult forms, teeth and sockets variably developed. Middle cambrianupper permian o Order strophomenida commonly concavo-convex valves with straight hinge lines and bilobed cardinal process. Pedicle foramen atrophied during ontogeny. Ordivician to permian o Order productidia spines. Small to gigantic strophenaceans with dorsal valves markedly smaller than ventral (pedicle) valves, sometimes conical; tubular spines. Spines may be on ventral hinge, or ventral valve only. Upper ordivician to upper permian, ?lower triassic Class Rhynchonellata biconvex strophic or astrophic shells articulaed by teeth and sockets, buttressed by brachiophores, delthyrium or pedicle foramen, smaller notothryium may be present, diductors, adductors and adjuster muscles, lophophore supports may develop into spirallum. Lower cambrian to recent o Order protorthida sall strophic shell with wide open delthyrium and notothryium, dental ridges, spondylium. Lower cambrian to upper devonian o Order orthida variably biconvex valves with straight hinge lines, open delthyria and notothryria and commonly simple linear cardinal process. Both punctate and impunctate forms. Lower cambrian to upper permian o Order pentamerida binconvex valves usually with curved hinge lines; spondylia and cruralia variably developed in ventral and dorsal valves. Lower cambrian to upper devonian
Order Rhynchonellida commonly biconvex and curved hinge lines; crura variablhy developed in dorsal valve. Occasionsal punctate forms. Lower ordivician to recent o Order atrypida binconves valves with dorsoventrally directed spiralia, with variably developed jugum. Ordivician to upper devonian o Order athyrida usually biconvex valves, short hinge line, posterolaterally directed spiralia. Upper ordivician to jurassic o Order spiriferida wide strophic hinges and laterally directed spiralia; both punctate and impunctate forms. Upper ordivician to upper permian o Order spiriferinida angled strophic hinges with laterally directed spiralia. Lower devonian to lower jurassic. o Order terebratulida - biconvex, with short curved hinge lines, an open pedicle foramen and short or long loop like brachidia. Lower devonian to recent o Order Thecideida similar to terebratulids with a punctate shell, usually attached by cementation without pedicle, diductors, adductions, square cardinal process. Upper triassic to recent Characteristic Inarticulate Articulate Shell composition CaCO3 / CaPO4 CaCO3 only, punctate, impunctate, pseudopunctate Hinge No hinge teeth or sockets Huge teeth, sockets Musculature Complete Simple; adductors and diductors Digestive system Complete; anus Incomplete, no anus
o
Life Habits: Burrower Sessile attached (pediculate) Recliner found in late permian, not good in sediment Cementer Swimmer caninids, almost flat Rudwickian method Zig-zags pliactions proposed as sediment eliminations, commisure of rhynconellids pumps