West Herts Community Midwives, Molly Menard Net Worth, Alan Schofield Obituary, Publix Soup Schedule 2020, Articles I

Specimen is approximately 8 cm in length. [28], The lamprey intestine has a typhlosole that increases the inner surface like the spiral valve does in some jawed vertebrates. Mouth ventral, oval, and suctorial. They're parasitic, normally feeding on fish during their adult phase. Ovicells and avicularia are present. Ostracoderms ( lit. Animals belonging to phylumChordata is characterised by the presence of the notochord, dorsal tubular nerve cord, gill-clefts and a post-anal tail. Class Osteichthyes: Examples Labeo rohita and Catla catla. Phylum Chordata possesses the following characteristic features: The Phylum Chordata Classification is shown through a flow chart given below: The Classification of the Phylum Chordata are as follows: Urochordata (Greek: Uro tail; chorde cord) is one of the subphyla of the Phylum Chordata and exhibits the following characteristics:i. They are ectoparasites on some fishes. They are true coelomates. As demonstrated in laboratory experiments by Drew Harvell (1984), spines can take up to two days to form, meaning that individuals zooids will be consumedbefore and while defenses are producedbut the colony will most likely survive. 4, UF 305771 (Shell 22), irregularly shaped kenozooids formed at the encounter edge between two abutting colonies (400 m). Cyclostomata is the modified and degenerate offshoot of the primitive vertebrate stalk. Class Chondrichthyes: Examples are Dogfish, Stingray, etc. As shown in the figure below, Cyclostomata diversity in the Jurassic peaked with approximately 30 genera, and 80 species, before declining at the end of the period. [20] Hagfishes and lampreys lack a thymus, spleen, myelin and sympathetic chain ganglia. Do you know how to answer the questions that cause some of the greatest grammar debates? They are known to be the only living vertebrates without true jaws, hence called Agnatha. Class Reptilia: Examples are garden lizard, snake, crocodile, etc. Class Mammalia: Examples are cats, dogs, human beings, etc. On the right is a cross-section view of a generic bryozoan zooid from the British Museum of Natural History's "A Guide to the Fossil Invertebrate Animals" (public domain). From 1831 onwards, the name bryozoan has been used; however, this name originally included an outwardly similar looking group, the Endoprocta. They have a streamlined, or boat-like or spindle body that offers resistance while flying.ii. They are only, Order 1: Petromyzontiformes (Gr., petros = stone; myzon = suck), Order 2: Myxiniform (Gr., myxa = slime; oidea = slime type), (A) Characters Resembling those of Amphioxus, (B) Characters More Primitive Than In Fishes (Differences From Fishes). Lamprey. Fill Out the Form for Expert Academic Guidance! Yet the same mechanisms are apparent in the mitochondria-rich cells in the gill epithelia of hagfishes, but never develops the ability to regulate the blood's salinity, even if they are capable of regulating the ionic concentration of Ca and Mg ions. Bryozoan: Archimedes wortheni (PRI 70774), Sam Kischnick; Creative Commons Attribution-NonCommercial 4.0 International, Wilson44691; Creative Commons CC0 1.0 Universal Public Domain Dedication, Lamiot; Creative Commons Attribution-Share Alike 4.0 International, Creative Commons Attribution-NonCommercial-Share Alike 4.0 International License. Mckinney, F. K., P. D. Taylor, and S. Lidgard. A variety of fossil bryozoans from the Ordovician of Estonia. Deuterostome - Wikipedia Stenolaematesand bryozoans, in generalwere hard hit by the end-Permian extinction and are rare in Triassic-aged rocks. The mucous membranes of hagfishes have a primitive typhlosole in the form of permanent zigzag ridges. Presence of cranium or brain box that accommodates the brain.iii. Watch the video above to see this process in action! Poorly developed lateral organs and in isolated pits. Like similar structures produced by other freshwater invertebrates (e.g., the water flea, Daphnia), statoblasts can also serve as an insurance policy against changing conditions. Division Gnathostomata: Examples are fish, birds, etc. In some groups, the operculum has evolved into more active defensive mechanisms, like mandibles to clamp onto predators or a long bristle to aid in sensing threats (and potentially to help keep the colony clean). The "vertebrate hypothesis" holds that lampreys are more closely related to gnathostomes than they are to the hagfish. on Sketchfab. Gills 5 to 16 pairs in lateral sac-like pharynx pouches, thus another class name Marsipobranchii. Hagfishes and lampreys are examples of Cyclostomata. Respiration is by lungs or gills.iv. Hagfishes. Cyclostomes are thought to have evolved in the ocean, and they still live in the ocean today. from the Ordovician Maquoketa Shale of DeKalb County, Illinois (PRI 76720). Autozooids function in feeding and excretion. Their skin is dry, the tough glands and it is covered by epidermal scales.ii. Although some cyclostomes encrust fleshy algae, the majority colonize hard substrates. All orders of Stenolaemata, except Cyclostomata, went extinct by the end of the Triassic. The form taken by bryozoan colonies can be highly variable, from gelatinous blobs to upright branching structures and sheet-like encrusters, but the general morphology of a zooid is similar across the classes. "Skeletal ultrastructure and phylogeny of cyclostome bryozoans". Give two examples of Cyclostomata. - BYJU'S On the left is a collection of freshwater Phylactolaemata bryozoans, hand drawn by Ernst Haeckel(public domain). As a result of the EUs General Data Protection Regulation (GDPR). Cyclostomata : Examples - Lamprey and Hagfish. The crocodile is an exception as it has a four-chambered heart.v. The nasal duct ends blindly in a pouch in lampreys but opens into the pharynx in hagfishes. Like the broader phylogeny, the relationship between different cheilostomes remains unclear. They breathe through lungs. An example of Agnatha (jawless vertebrate)/cyclostomata is Q. Thus, in addition to reproducing asexually through statoblasts, phylactolaemates also reproduce sexually. Phylum Chordata is one of the phyla that belongs to the Kingdom Animalia which includes all the vertebrates and invertebrates. For example, the presence of a cerebellum, myelin on nerves, and lenses on the eyes separate these two groups and put . Cyclostomatida, or cyclostomata (also known as cyclostomes), are an ancient order of stenolaemate bryozoans which first appeared in the Lower Ordovician. Regardless of environment, all bryozoans feed by filtering tiny particles from the water column using their lophophores. Predation on bryozoans and its reflection in the fossil record. The zooecium secretes calcium carbonate to form a skeleton in groups like the cheilostome Gymnolaemata, or gelatinous material in Phylactolaemata (learn more about these groups in the sections below). Besides these, the ammocoete larva of lampreys resembles Amphioxus as follows: The dorsal and caudal fins are continuous. In the Cyclostomata the primary embryo undergoes repeated fission without developing definite organs, and each of the numerous pieces so formed becomes a free larva, which possesses no alimentary canal. Leading AI Powered Learning Solution Provider, Fixing Students Behaviour With Data Analytics, Leveraging Intelligence To Deliver Results, Exciting AI Platform, Personalizing Education, Disruptor Award For Maximum Business Impact, Copyright 2023, Embibe. Gymnolaemates are the most abundant and diverse bryozoans today, comprising at least 80% of known bryozoan species. 6, close-up of a zooid with incomplete ovicell and distolateral spine bases (100 m)." Cyclostomatida, or cyclostomata (also known as cyclostomes ), are an ancient order of stenolaemate bryozoans which first appeared in the Lower Ordovician. Series B. The Cyclostomata are the living agnathans (Gr., cyclos = circular + stoma = mouth), they are primitive in many respects but specialized in others. They are poikilothermic animals, and the body is divisible into head, neck, trunk and tail.iii. Check All That Apply Many characteristics are found in lampreys and absent in hagfish. (c) What is a colloid ? As discussed by Taylor and Waeschenbach (2015), the evolution and eventual rise to prominence by the cheilostomes can be considered as a three-phase process (see figure below). The mechanism of protrusion in the Cyclostomata is a subject which requires further examination. 1.1 Phylogenetics They found throughout the late Cretaceous period (80-65 million years ago) of North America. Segmental musculature (myotomy) but with little change from head to tail. Hind limbs are shifted forward to balance the body while walking.vi. In free-walled (or double-walled) cyclostomes, the exterior frontal walls of the zooids are uncalcified; autozooids have either a polygonal aperture bounded by vertical interior walls, or a subcircular aperture in species with kenozooids filling the spaces between the autozooids. Since that time, the third phase of cheilostomes diversity has been defined by relatively constant diversity. This order contains the lampreys, which are eel-like fish that attach themselves to other fish and suck their blood. At the end of the video above, you can see hundreds of tiny statoblasts on the hand of the person holding the colony. Instead of feeding, heterozooids specialize to perform other functions critical to the survival and reproduction of the colony. Kenozooids, the last type of zooid, are employed to strengthen the colony and build structural elements. They are known as cartilage fishes with a cartilaginous endoskeleton. In contrast, freshwater bryozoans are simultaneous hermaphrodites, with all individuals capable of producing both sperm and egg. (PRI 76724) Left image by Sam Kischnick; Creative Commons Attribution-NonCommercial 4.0 International license. Cyclostomata. Merriam-Webster.com Medical Dictionary, Merriam-Webster, https://www.merriam-webster.com/medical/Cyclostomata. The term does not often appear in classifications today because it is paraphyletic (excluding jawed fishes) (may also be polyphyletic if anaspids are closer to cyclostomes) and thus does not correspond to one evolutionary lineage. ADVERTISEMENTS: Examples: Labiostomella, Membranipora, Conopeum, Callopora, Bugula. The "cyclostome hypothesis", on the other hand, holds that lampreys and hagfishes are more closely related, making cyclostomi monophyletic. Each slime gland is surrounded by connective tissue and striated muscle fibres that help exude the slime upon stimulation. The brain is well developed, and respiration is by the lungs.x. Osteichthyes: Classification, Characteristics and Examples - BYJU'S What are the \(5\) characteristics of chordates? Copyright 2023. . i. Agnatha (Greek: Gnathos mouth; a without) members have a mouth that is circular and absence of jaws surrounding the mouth.ii. Give two examples of solutions. Maximum length of specimen is approximately 2.5 cm. The original caption, and key, for the rightside image reads: "Diagram of structure of a typical Bryozoan zooid, as seen in a vertical cut down the middle. The purported bore holes in bryozoans are quite small, however, and it is challenging to assign them to a particular type of trace making predator. Give two examples of suspensions. Two chambered heart, breathe by means of gills, cold blooded or poikilothermal. excurrent Gill. Gills are not covered by the operculum. For the superclass of jawless fish, see. In the second phase, these early cheilostomes diversified rapidly until reaching peak Mezosoic diversity at the end of the Cretaceous. "Agnatha", Clade Cyclostomata. Class 2 Chondrirchthyes. Additional Information Sea Urchin Sea Urchin common name is Echinus. (c) What is a colloid ? It includes Vertebrata characterized by two pairs of limbs. Cheetham, A. H. 1986. Bryozoans may also be subject to incidental predation, as small species of fish, shrimp, and crab can be found living amongst the branches of erect forms. They exhibit the following features: Their skin is moist and smooth due to mucus glands.ii. The body has a trunk and tail. [15] The embryonic development of hagfishes was once held to be drastically different from that of lampreys and gnathostomes, but recent evidence suggests that it is more similar than previously thought, which may remove an obstacle to the cyclostome hypothesis. They are viviparous, sexes are separate, and fertilization is internal and development is direct.xii. E, unidentified cribrimorph ascophoran, NHMUK BZ7735, Campanian, Needs Camp, East London, South Africa; reduced spinocystal frontal shield becoming overgrown (arrows) by the outer walls of encircling kenozooids. Other zooids capture the sperm, much like capturing food particles with their lophophores, and use this to fertilize their eggs. However, there are some elements of the novel that resemble the characters of amphioxus. The spiral valve in the latter develops by twisting the whole gut, while the lamprey typhlosole is confined to the mucous membrane of the intestines. They have an elongated body with \(6\) to \(15\) pairs of gill slits for respiration. They possess two openings on their body surface mouth and atriopore.ii. Hagfishes have approximately 150 to 200 slime glands alongside the side of the body. The ears have a fleshy ear pinna.v. 1, part of the colony (200 m). Whereas colonies of some species may produce only one statoblast, others have been reported to produce more than 800,000 of these asexual reproductive structures. Lamprey larvae live in freshwater and are called ammocoetes, and are the only vertebrates with an endostyle, an organ used for filter feeding that is otherwise found only in tunicates and lancelets. Tempo of evolution in a Neogene bryozoan: rates of morphologic change within and across species boundaries. The mucus contents are a protein plus and carbohydrate that binds to water and expands to form a loose jelly type. In the bottom middle of the image, two thin vibricula can be seen extending beyond the lophophores. Original figure and caption from Di Martino et al. Jawless Vertebrates: Historical Resume and Classification Cephalochordata (Greek: Cephalos head; chorde cord) is one of the subphyla of the Phylum Chordata and exhibits the following characteristics:i. D, Pelmatopora marsupitorum Lang, NHMUK D41056, Campanian, Chalk, RottingdeanSaltdean, Sussex, UK; cribrimorph ascophoran (Infraorder Acanthostega) showing autozooids with characteristic frontal shields consisting of overarching, laterally and medially fused spines, and surrounded by small avicularia and elongate kenozooids (e.g. Left image by Jeff Goddard; Creative Commons Attribution-NonCommercial 4.0 International license. Class Amphibia: Examples are a frog, Salamandra, etc. They are homeothermic animals, and some are secondarily adapted for living in water Whales.iii. Bryozoa. The digestive system lacks a belly. In avicularia, the zooecium and operculum form a beak-like structure that is capable of latching on to potential predators, deterring them from consuming the colony. Though the class is primarily composed of marine species, a few Stenolaemata also occur in freshwater. Bryozoa - Digital Atlas of Ancient Life The heart is four-chambered with two auricles and two ventricles.ix. III. They have two pairs of limbs, a pair of forelimbs with four digits and hindlimbs with five digits.iv. Stenolaemates are the oldest bryozoans and date from the Early Ordovician Epoch (505 million to 478 million years ago) onwards. Members can be divided into two groups, namely, flying birds like parrots, pigeons, etc., and flightless birds like ostrich, kiwi, etc. [31].mw-parser-output table.clade{border-spacing:0;margin:0;font-size:100%;line-height:100%;border-collapse:separate;width:auto}.mw-parser-output table.clade table.clade{width:100%;line-height:inherit}.mw-parser-output table.clade td.clade-label{min-width:0.2em;width:0.1em;padding:0 0.15em;vertical-align:bottom;text-align:center;border-left:1px solid;border-bottom:1px solid;white-space:nowrap}.mw-parser-output table.clade td.clade-label::before,.mw-parser-output table.clade td.clade-slabel::before{content:"\2060 "}.mw-parser-output table.clade td.clade-fixed-width{overflow:hidden;text-overflow:ellipsis}.mw-parser-output table.clade td.clade-fixed-width:hover{overflow:visible}.mw-parser-output table.clade td.clade-label.first{border-left:none;border-right:none}.mw-parser-output table.clade td.clade-label.reverse{border-left:none;border-right:1px solid}.mw-parser-output table.clade td.clade-slabel{padding:0 0.15em;vertical-align:top;text-align:center;border-left:1px solid;white-space:nowrap}.mw-parser-output table.clade td.clade-slabel:hover{overflow:visible}.mw-parser-output table.clade td.clade-slabel.last{border-left:none;border-right:none}.mw-parser-output table.clade td.clade-slabel.reverse{border-left:none;border-right:1px solid}.mw-parser-output table.clade td.clade-bar{vertical-align:middle;text-align:left;padding:0 0.5em;position:relative}.mw-parser-output table.clade td.clade-bar.reverse{text-align:right;position:relative}.mw-parser-output table.clade td.clade-leaf{border:0;padding:0;text-align:left}.mw-parser-output table.clade td.clade-leafR{border:0;padding:0;text-align:right}.mw-parser-output table.clade td.clade-leaf.reverse{text-align:right}.mw-parser-output table.clade:hover span.linkA{background-color:yellow}.mw-parser-output table.clade:hover span.linkB{background-color:green}, "Cyclostomata" redirects here. [1] It consists of 7+ suborders, 59+ families, 373+ genera, and 666+ species. Kenozooids are used for structural purposes, such as creating divisions between colonies. "Generic diversity of cheilostome bryozoans based on stage level data published by Ostrovsky et al. Median single nostrils, instead of paired. Paired fins are absent. Myxinoidea, Subclass 2. The body-wall is extensively calcified in the Cyclostomata . For When 'Lowdown Crook' Isn't Specific Enough. Uniramus stays in one straight form. Nostril is single and median. 1.3 Reproduction and Development of patients (%) Age, years 18-29 2 (0.8) 30-39 15 (6.0) 40-49 36 (14.4) 50-59 112 (45.1) 60-69 58 (23.4) 70-79 13 (5.3) 80-93 2 (0.8) Sex Male 167 (67.1) Female 82 (32.9) Location Hand 188 (75.9, : Petromyzontiformes Family : Petromyzontidae. In addition to branching and encrusting forms (e.g., Polypora), these early bryozoans also formed mound-like structures (e.g., Prasopora) and more eccentric forms such as the corkscrew-like Archimedes. Class - Aves They have a four-chambered heart. Fibrous and cartilaginous Endoskeletons. I agree to the terms and conditions and privacy policy. Most fossil agnathans, such as galeaspids, thelodonts, and osteostracans, are more closely related to vertebrates with jaws (called gnathostomes) than to cyclostomes. Class Cyclostomata (Greek: Cyclos - circular; stome - mouth) is a class of Division Agnatha and exhibits the following characteristics: i. This article is about an order of bryozoan invertebrates. In many modern bryozoans, eggs are not released into the water column. Additionally, both amphioxus and the novel are relatively simple and straightforward in their presentation. and They superficially mimic eels. [6][7] Cyclostomes seem to have split off before the evolution of dentine and bone, which are present in many fossil agnathans, including conodonts. Q.4. Different types of teeth are present (heterodont condition) embedded in sockets of the jawbones (thecodont). 91 988-660-2456 (Mon-Sun: 9am - 11pm IST), Explore all Vedantu courses by class or target exam, starting at 1350, Full Year Courses Starting @ just Bryozoans are filter feeding invertebrates and can be found in both freshwater and marine habitats, where they are often easy to miss because of their small size and cryptic lifestyle (e.g., encrusting seashells, rocks, or kelp). Both hagfishes and lampreys have a single gonad, but for different reasons. The body in birds is covered by feathers made up of keratin protein.v. These are the first true terrestrial vertebrates and exhibit the following characters:i. However, almost all cyclostome species have enlarged zooids - gonozooids - for brooding larvae, and some species also possess non-feeding zooids - kenozooids - with space-filling and structural roles. . Image by Lamiot; Creative Commons Attribution-Share Alike 4.0 International license. Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012. All birds fall in this category. (ii) Angiosperms : These are flowering plants which develop seeds inside an organ which turns into a fruit. They have an elongated body with \ (6\) to \ (15\) pairs of gill slits for respiration. Here are some of the important facts related to phylum chordata: Which is the only poisonous lizard in the world? For example, the phylogenetic hypothesis put forward by Telford et al. Morphologically, they resemble eels. In the amphioxus, as has been said, the cranio-spinal axis alone exists; the Cyclostome fishes are but a step higher. Jaws, exoskeleton, and paired fins are absent. For more than 50 million years, cheilostomes were represented by only a handful of genera. What are ammocoetes? View Google Privacy Policy. This is only one proposed hypothesis of relationship, however, as other phylogenies have placed Stenolaemata basal to the Gymnolaemata. I want to receive exclusive email updates from YourDictionary. Telford, M. J., G. E. Budd, and H. Philippe. Brain relatively small or generalised. Food tract ciliated straight and without extensive regional specialization. hello friends Always welcome to my educational platform, If my videos is Informative, helpful, & Interesting than kindly like share and subscribe our chann. Watch a variety of different bryozoans feed in this video, "Bryozoa - Lophophorata" by Ioly Schwartz. There are grammar debates that never die; and the ones highlighted in the questions in this quiz are sure to rile everyone up once again. This is the second time a biomineralized skeleton evolved in bryozoansthe first was by the early Stenolaemata. The frame is elongated and Eel like. IV. an, anus; ap, aperture; b.c, body-cavity; c.p, communication pore; d, diaphragm; ect, ectoderm; end, endoderm; f, funiculi; n, nerve-ganglion; o, orifice [mouth]; oes, oesophagus ; op, operculum; r.m, retractor muscle; st, stomach; T, tentacles; t.s, tentacle sheath." They are parasitic, usually eating fish when they are older. Like other small, invertebrate organisms, bryozoans are considerably understudied, and much more extensive sampling and analysis of living species will be needed to parse out these relationships. 239-261). Octopus Intracolony variation in zooid size in cheilostome bryozoans as a new technique for investigating palaeoseasonality. Predator-induced defense in a marine bryozoan. Length of specimen is approximately 11 cm. Currently, cyclostomes seldom constitute more than 20% of the species recorded in regional bryozoan faunas. Subphylum Vertebrata is again divided into two sections, namely, Section Agnatha and Section Gnathostomata. In the Jurassic and Early Cretaceous, cyclostome stenolaemates dominated the bryozoan fauna but gave way to the newly evolved cheilostome gymnolaemates by the end of the Cretaceous. Spinal news Dorsal and ventral roots joined. They are poikilotherms or cold-blooded animals and lack the capacity to regulate their internal body temperature. Jansen A. Smith, Paleontological Research Institution, Ithaca, New York. 2019. Shark or scoliodon is known as dog fish and torpedo is known as electric ray. Specimen is from the collections of thePaleontological Research Institution, Ithaca, New York. Though predation on bryozoan was also likely common in the geological past, evidence of such predation is sparse in the fossil record. In their various environments, bryozoans are occasionally consumed by predators, such as the nudibranch in the video below. What is the currently accepted meanings for the word species? The notochord extends from head to tail region, and it is persistent throughout their life.ii. a cyclostome vertebrate; a lamprey or hagfish. Polymorphism of zooids is less conspicuous than in cheilostomes. Median fins with cartilaginous fine rays, but no appendages paired. Anadromous: Ascend up rivers and streams to spawn In some groupsand likely in primitive, ancestral Paleozoic bryozoansboth eggs and sperm are released into the water, where they form a free-swimming larva, and eventually new colonies. Example of Clade Petromyzontida. Morphologically, they resemble eels. The vast majority of bryozoans are colonial, though several exceptions exist, such as the aptly named genus Monobryozoon. No spinal valve in the intestine, or even a poorly formed spiral valve.9. 6.6: Expressed Sequence Tags - Biology LibreTexts Phylum Ectoprocta: Features, Classification and Affinities Post the Definition of Cyclostomata to Facebook, Share the Definition of Cyclostomata on Twitter. Wasson B & de Blauwe H (2014). (a) What is meant by a solution ? To date, more than 17,800 species of fossil bryozoans have been described and more than 6,000 living species are known. 2023. Cheilostome diversity remained low until the Cenomanian, increased rapidly through the Late Cretaceous, peaking in the Maastrichtian, declined at the KT boundary and at the end of the Danian, and increased again through most of the Palaeogene." Q.2. (b) What is suspension ? As shown in the figure below, Cyclostomata diversity in the Jurassic peaked with approximately 30 genera, and 80 species, before declining at the end of the period. iv. These names are based on the position of the anus relative to the animals crown-like feeding apparatuses. Figure and caption from Vieira et al. The body has an exoskeleton made up of epidermal hair.ii. All post-Palaeozoic cyclostomes have interzooidal connections via pores in the vertical walls separating adjacent zooids. Despite their small size, marine bryozoans are abundant in many fossil assemblages thanks to the preservability of their hard calcium carbonate skeletons. The torches. Which of the following accurately describes members of Cyclostomata? Sexes are separate, animals are oviparous, and fertilization is external. There is also some evidence to suggest that shell-boring predators, such as muricid and naticid snails (read more about drilling predation), consume bryozoans. [20], Hagfishes and lampreys lack a thymus, spleen, myelin and sympathetic chain ganglia. Instead, sperm are released by sperm donating individuals and are captured by the lophophores of egg donating individuals. They are considered to be the only living vertebrate without true jaws and are thus called Agnatha. Possibly the resemblance of those two classes is the product of convergent evolution. "Stenolaemate bryozoan tree with known ranges of orders. The Digital Atlas of Ancient Life project is managed by thePaleontological Research Institution, Ithaca, New York. They are the only extant vertebrates lacking genuine jaws, which is why they are termed Agnatha. They have no scales, and their skin is smooth. They are only vertebrates without genuine jaws, subsequently referred to as Agnatha. Extension of the lophophore is carried out differently in different groups but can be thought of generally as an increase of pressure in the zooecium, forcing the lophophore outward. Reinterpretation of the Cambrian bryozoan'Pywackia as an octocoral. Cyclostomata have a long, eel-like body and a smooth skin. The word Cyclostomata means "round mouths. 'shell-skins') are the armored jawless fish of the Paleozoic Era. Petromyzon is an example of Cyclostomata. Cyclostomata is the modified and degenerate offshoot of the primitive vertebrate stalk. To do so, sperm is released from individual zooids into the water, where it circulates about the colony. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Trick Cyclostomata Examples and Characters || Animal Kingdom iii. Ans: The \(5\) characteristics of chordates are as follows: I.