Relative eye size in elasmobranchs. The nervous system of a fish is similar to that of other vertebrates. https://doi.org/10.1007/978-3-319-47829-6_1018-1, DOI: https://doi.org/10.1007/978-3-319-47829-6_1018-1, eBook Packages: Springer Reference Behavioral Science and PsychologyReference Module Humanities and Social Sciences, DOI: https://doi.org/10.1007/978-3-319-47829-6_1018-2, Over 10 million scientific documents at your fingertips, Not logged in Brain Structure and Function, 220, 11271143. ), Biology of sharks and their relatives (pp. Maruska, K. P. (2001). 2023 Springer Nature Switzerland AG. This lesson will discuss the nervous system of fishes in more detail, including the anatomy of the fish nervous system, how fish brain anatomy compares to that of a human, and the two components of a fish's nervous system. Sharks/relatives produce less offspring than other fish, but they are larger and typical survive longer. CrossRef Rays: Electric ray, Stingray, Manta ray, etc. Corwin, J. T. (1978). [5] They have several sensory organs which provide information to be processed. They dont reach sexual maturity until 156 22 years! Question: What does that mean for ovoviviparous organisms in terms of the evolutionary continuum? Classification of Pisces. Question: What benefits would having a jaw confer to an organism? Journal of Experimental Biology, 213(20), 34493456. Fertilization occurs internally. Encyclopedia of Animal Cognition and Behavior, https://doi.org/10.1007/978-3-319-55065-7_1018, Shipping restrictions may apply, check to see if you are impacted, https://doi.org/10.1016/j.jphysparis.2008.10.005, https://doi.org/10.1016/j.semcdb.2020.03.012, https://doi.org/10.1111/j.1095-8649.2011.03214.x, https://doi.org/10.1007/s11160-010-9162-x, https://doi.org/10.1017/S0952523809990150, https://doi.org/10.1113/jphysiol.1951.sp004638, https://doi.org/10.1111/j.1749-4877.2008.00130.x, https://doi.org/10.1007/s00429-014-0705-0, Reference Module Humanities and Social Sciences, Tax calculation will be finalised during checkout. PubMed What are they homologous to? Springer, Cham. Manta Ray. They are oviparous in some cases and viviparous in others. (Lond. Journal of Experimental Biology, 207(20), 34633476. 393434). https://doi.org/10.1113/jphysiol.1951.sp004638. Nervous System- they have 5 parts brain which includes the highly developed olfactory region. Sensing temperature without ion channels. Growth of a few shark species has been measured or estimated by the differences in length at the times of tagging and recapturing specimens. The relation of inner ear structure to the feeding behavior in sharks and rays. Chondrichthyes is a class that contains sharks, skates, rays and chimeras. This is a form of asexual reproduction in which an embryo develops without being fertilized. A. Musick, & M. R. Heithaus (Eds. (1995). It includes Chimaeras, also known as ghost sharks. Test of the mechanotactile hypothesis: Neuromast morphology and response dynamics of mechanosensory lateral line primary afferents in the stingray. Their inner ears consist of 3 large semicircular canals which aid in balance and orientation. Brown, B. R. (2003). We typically think of oviparousity as the most primitive and viviparousity as more advanced. Lisney, T. J. Die Parietalorgane. Most species have large well-developed eyes. Montgomery, J. C., Windsor, S., & Bassett, D. (2009). It is responsible for detecting signals and sending responses. Morphology of the mechanosensory lateral line system in elasmobranch fishes: Ecological and behavioral considerations. The first Cartilaginous fishes evolved from Doliodus-like spiny shark ancestors. American Museum Novitates, 2017(3875), 115. - 139.59.14.115. Didier, D. A. Test of the mechanotactile hypothesis: Neuromast morphology and response dynamics of mechanosensory lateral line primary afferents in the stingray. Kempster, R. M., McCarthy, I. D., & Collin, S. P. (2012). Lowenstein, O., & Roberts, T. D. M. (1951). She is a current PhD student in biology at Wake Forest University, and has been teaching undergraduate students biology for the last three years. Pectoral morphology in Doliodus: Bridging the acanthodian-chondrichthyan divide. Afferent signals come from muscles, sensory organs, and structures to provide information to the central nervous system. Brain Structure and Function, 220, 11271143. The fish brain is generally divided into four different components. Boca Raton: CRC Press. They have excellent auditory and low light detecting receptors. Web the chondrichthyes are the cartilaginous fishes, such as sharks and rays, while the osteichthyes are the bony fishes. Responses are generated and sent to specific structures via motor neurons. Journal of Morphology, 274, 447455. Electroreception in marine fishes: Chondrichthyans. Systematic Ichthyology Laboratory, Department of Zoology, University of Braslia, Braslia, Brazil, Fauna and Protected Areas Laboratory, Department of Forest Engineering, University of Braslia, Braslia, Brazil, Laboratory of Vertebrate Comparative Anatomy, Department of Zoology, University of Braslia, Braslia, Brazil, Laboratory of Ichthyology, Department of Zoology, University of So Paulo, So Paulo, Brazil, You can also search for this author in The disk of the eastern Pacific round stingray (Urolophus halleri) increases in width on the average from 75 mm (3 inches) at birth to 150 mm (6 inches) when mature (that is, at 2.6 years old). Electroreception in marine fishes: Chondrichthyans. ), Biology of sharks and their relatives (pp. https://doi.org/10.1113/jphysiol.1951.sp004638. Class: Chondrichthyes. 2023 The Biology Classroom. Nutrition is crucial to children's physical and mental development. Environmental Biology of Fishes, 60(13), 4775. Let's delve into the structure and function of the central nervous system in bony fish - the brain and spinal cord - as well as the peripheral nervous system - branching nerves that extend throughout the body. At the caudal, or back, end of the brain lies the hindbrain, or metencephalon. (2013). Brain, Behavior and Evolution, 69(4), 266279. Create your account. Brain Structure and Function, 220, 11271143. Then, with the mouth still closed, they contract the bucco-pharyngeal cavity and gill pouches, and the gill slits are opened to expel the water. General Characteristics of Chondrichthyes Their digestive systems have spiral valves and, with the exception of Holocephali, a cloaca. Each gill has between five and seven blades. Lisney, T. J. The few published descriptions of mating sharks and rays are probably characteristic of the entire group. Sharks breathe chiefly by opening the mouth while expanding the mouth-throat (bucco-pharyngeal) cavity and contracting the gill pouches to close the gill slits. https://doi.org/10.1007/978-3-319-47829-6_1018-2, DOI: https://doi.org/10.1007/978-3-319-47829-6_1018-2, eBook Packages: Springer Reference Behavioral Science and PsychologyReference Module Humanities and Social Sciences, DOI: https://doi.org/10.1007/978-3-319-47829-6_1018-1, Over 10 million scientific documents at your fingertips, Not logged in The Lateral line system has modified epithelial cells located externally which sense motion, vibration, and pressure in the water around them. Familiar bony fishes such as goldfish, trout, and bass are members of the most advanced subgroup of bony fishes, the teleosts, which developed lungs and first invaded land. 2023 Springer Nature Switzerland AG. Morphometric and ultrastructural comparison of the olfactory system in elasmobranchs: The significance of structurefunction relationships based on phylogeny and ecology. Electroreception. The lateral line system of nerves provides osteichthyes with a sense of hearing, in the form of vibrations in the water, which can help osteichthyes avoid predators and detect prey. [13] Dating back to the Middle and Late Ordovician Period, many isolated scales, made of dentine and bone, have a structure and growth form that is chondrichthyan-like. Chondrichthyans have a closed circulatory system. Is the longest-lived vertebrate animal known at 392 120 years! Caputi, . The Journal of Physiology. Journal of Physiology-Paris, 102(46), 256271. https://doi.org/10.1002/jmor.20106. Gardiner, J. M., Hueter, R. E., Maruska, K. P., Sisneros, J. The central nervous system contains the brain and spinal cord. 2005). https://doi.org/10.1007/BF00751027. https://doi.org/10.1007/s11160-010-9162-x. Ovoviviparous (Aplacental yolk sac viviparous). However, many of their life history traits, such as low fecundity, the production of small numbers of highly precocious young, slow growth rates, and late maturity, make them highly . Hart, N. S. (2020). Didier, D. A. In later forms, each pair of fins became ventrally connected in the middle when scapulocoracoid and puboischiadic bars evolved. Behavior and physiology of mechanoreception: Separating signal and noise. Animals that possess jaws are known as gnathostomes, meaning "jawed mouth.". Veronica Slobodian . There are so many misconceptions about this class of vertebrates; education is the first step to protecting sharks which in turn will help protect food webs and biodiversity in our oceans. Journal of Morphology, 250(3), 236264. Sensory physiology and behavior of elasmobranchs. Chondrichthyes (/kndrki.iz/; from Ancient Greek (khndros)'cartilage', and (ikhths)'fish') is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. Nutrients supplied by blood vessels. In fishes with excellent senses of smell, the telencephalon is enlarged. Springer, Cham. Academic Press. A., Casper, B. M., Mann, D. A., & Demski, L. S. (2012). Meredith, T. L., & Kajiura, S. M. (2010). (Fun fact: Bull Sharks can live in both fresh and salt water and have been known spotted 4000km up the Amazon river, in Ganges river, the Mississippi, and in Lake Nicaragua! CrossRef Google Scholar Gruber SH (1977) The visual system of sharks; adaptations and capability. Include what previous structure the jaw is thought to have evolved from. In J. C. Carrier, J. I would definitely recommend Study.com to my colleagues. The Osteichthyes Respiratory System. Carrier, J. Musick, & M. Heithaus (Eds. In addition, these two types of fish are classified under different taxonomic groups - the cartilaginous fish fall into the class Chondrichthyes and the bony fish into the superclass Osteichthyes. Carrier, J. Musick, & M. Heithaus (Eds. They bring water into their bodies using one of two methods: Ram ventilation - requires forward movement by the organism. Also, they have very powerful nostrils and olfactory organs. 1254). The species in this class have a flexible skeleton made of cartilage instead of bone. The nervous system is composed of the nerves, spinal cord, and brain. In general, pelagic species must keep swimming to keep oxygenated water moving through their gills, whilst demersal species can actively pump water in through their spiracles and out through their gills. Many larger, pelagic species, such as the mackerel sharks (Lamnidae) and the thresher sharks (Alopiidae), no longer possess them. They are jawed vertebrates, with skeletons made of cartilage instead of bone. Pectoral morphology in Doliodus: Bridging the acanthodian-chondrichthyan divide. American Museum Novitates, 2017(3875), 115. Signals are sent out to structures via somatic motor nerves or visceral motor nerves. All other trademarks and copyrights are the property of their respective owners. Provided by the Springer Nature SharedIt content-sharing initiative, Over 10 million scientific documents at your fingertips, Not logged in Ampullae of Lorenzini are a network of small jelly filled pores called electroreceptors which help the fish sense electric fields in water. A review of the sensory biology of chimaeroid fishes (Chondrichthyes; Holocephali). The peripheral nervous system contains the many nerves that extend from the brain and spinal cord and articulate with other structures in the body. They have a complex nervous system with a brain that connects to a spinal chord. Skates, stingrays, guitarfishes, and angel sharks frequently reverse the direction of flow through the spiracles, apparently to clear them of foreign matter. Rays are worth an economical amount. Capture-induced premature birth and abortion (collectively called capture-induced parturition) occurs frequently in sharks/rays when fished. The nervous system comprises of the brain and ten pairs of the cranial nerves. Chondrichthyes' sensory systems are part of the nervous system responsible for receiving external and internal stimuli and translating them into nerve impulses that are transmitted to the. A fish's spinal cord transmits motor messages to its peripheral nerves, and sends sensory messages back to the brain. As we will see, the various nerves of the peripheral nervous system branch throughout the body. Meredith, T. L., & Kajiura, S. M. (2010). Litherland, L., Collin, S. P., & Fritsches, K. A. (1990). Some nerves come directly from the brain and are responsible for picking up important sensory information such as taste, smell, and sight. In: Vonk, J., Shackelford, T.K. https://doi.org/10.1111/jfb.13922. Mucous glands exist in some species, as well. injured/weakened prey), Have a U-shaped stomach (Not as complex as humans), Stomach leads to the intestine which is called the. Electroreceptors are organs that detect electric signals in water and are found on the lateral line running down the side of a fish. Write the difference between Chondrichthyes and Osteichthyes. B., & Kajiura, S. M. (2019). [14][15][16], The earliest unequivocal fossils of acanthodian-grade cartilaginous fishes are Qianodus and Fanjingshania from the early Silurian (Aeronian) of Guizhou, China around 439 million years ago, which are also the oldest unambigous remains of any jawed vertebrates. In chondrichthyans, the nervous system is composed of a small brain, 8-10 pairs of cranial nerves, and a spinal chord with spinal nerves. In O. M. Johari (Ed. Whale sharks, the second-largest vertebrae and the largest fish, measure up to 15 meters in length. Academic Press. Maruska, K. P., & Tricas, T. C. (2004). Journal of Morphology, 274, 447455. There are many nerves that branch off from the spinal cord, bringing sensory messages in from the skin surface (somatic sensory) and sending motor messages outward to move muscles (somatic motor). [12] Recent studies vindicate this, as Doliodus had a mosaic of chondrichthyan and acanthodian traits. Has a high concentration of a toxin trimethylamine N-oxide which causes the meat to be toxic if not treated. The somatotopic organization of the olfactory bulb in elasmobranchs. Comparing reproductive methods in sharks [Video] This is a great resource for clarifying these methods! By the start of the Early Devonian, 419 million years ago, jawed fishes had divided into three distinct groups: the now extinct placoderms (a paraphyletic assemblage of ancient armoured fishes), the bony fishes, and the clade that includes spiny sharks and early cartilaginous fish. https://doi.org/10.1242/jeb.01140. Vigh-Teichmann, I., Vigh, B., Silva, M. M., & Aros, B. The Respiratory System Part 1: Structures and Mechanisms of Breathing; The Respiratory System Part 2: Regulation of Breathing . Cell and Tissue Research, 303(3), 391401. Important note: Oviparous, viviparous, ovoviviparous are not terms exclusive to sharks! In the gills, the blood picks up oxygen from the surrounding water and leaves the gills in arteries, which goes back to the body. Schluessel, V., Bennett, M. B., Bleckmann, H., Blomberg, S., & Collin, S. P. (2008). CrossRef In females, the cloaca serves both as a reproductive organ and as an excretory organ. The Australian school shark (Galeorhinus australis) grows about 80 mm (3 inches) in its first year and about 30 mm (1 inch) in its 12th year. Some rare species are viviparous. In A. Oppel (Ed. However, there is currently no evidence of this. (1990). With this, fishes can detect when the water around them moves, alerting them of a passing nearby fish. 304 lessons Pectoral morphology in Doliodus: Bridging the acanthodian-chondrichthyan divide. Visual Neuroscience, 26(4), 397. https://doi.org/10.1017/S0952523809990150. In Seminars in Cell & Developmental Biology. Vertebrates comparative anatomy, function, evolution, 7th edn. A., Castell, M. E., Aguilera, P. A., Pereira, C., Nogueira, J., Rodrguez-Cattaneo, A., & Lezcano, C. (2008). Vigh-Teichmann, I., Vigh, B., Silva, M. M., & Aros, B. A review of the sensory biology of chimaeroid fishes (Chondrichthyes; Holocephali). This means that fish are capable of feeling stimuli related to pain. The peripheral nervous system contains any of the nerves found throughout the body that are not contained within the central nervous system. Jaws developed over time from the gill arches, which support the gills, of jawless fish. In: Vonk, J., Shackelford, T. (eds) Encyclopedia of Animal Cognition and Behavior. Sensory biology of elasmobranchs. The lack of air bladders means they need to swim constantly to avoid sinking. Caputi, . The somatotopic organization of the olfactory bulb in elasmobranchs. This is what allows them to sense the things around them. The principle component of shark liver oil is called squalene. Studnicka, F. K. (1905). 11051112). Hart, N. S. (2020). Fish contain pain receptors called nociceptors like humans do. The notochord is gradually replaced by a vertebral column during development, except in Holocephali, where the notochord stays intact. Also, most chordates are dioecious, meaning that the males and females of species are different (''di . Lisney, T. J., & Collin, S. P. (2007). Encyclopedia of Animal Cognition and Behavior pp 13671376Cite as. There is no parental care after birth; however, some chondrichthyans do guard their eggs. They contain a central nervous system containing a brain and spinal cord and a peripheral nervous system containing the various nerves throughout the body. https://doi.org/10.1002/jmor.1068. Chondrichthyes' sensory systems are part of the nervous system responsible for receiving external and internal stimuli and translating them into nerve impulses that are transmitted to the central Chondrichthyes is further subdivided into two subclasses: Elasmobranchii: In Greek, elasmo means Plate and branchia means gill, hence we can tell that long and broad flattened gills are the characteristics of these fishes. One of the primary characteristics present in most sharks is the heterocercal tail, which aids in locomotion.[2]. Die Parietalorgane. Phylogenetic systematics of extant chimaeroid fishes (Holocephali, Chimaeroidei). ), Scanning electron microscopy (Vol. https://doi.org/10.1002/jmor.10661. Describe how the Ampullae of Lorenzini helps Chondrichthyans navigate and migrate. This also helps the animals to prey on one another. Electroreceptors are a sensory organ that can detect electric signals. Within the infraphylum Gnathostomata, cartilaginous fishes are distinct from all other jawed vertebrates. These signals help a fish to maintain homeostasis, which is the state of having a consistent internal environment. This is most likely a secondary evolved characteristic, which means there is not necessarily a connection between the teeth and the original dermal scales. Hammerhead sharks have evolved to have more ampullae due to the evolutionary benefits conferred. ), Biology of sharks and their relatives (pp. Electroreception, electrogenesis and electric signal evolution. Visual Neuroscience, 26(4), 397. https://doi.org/10.1017/S0952523809990150. In Seminars in Cell & Developmental Biology. Study fish brain anatomy. Skates, which sometimes hold the lower surface of the head slightly above the bottom, may inhale some water through the mouth; mantas, which have small spiracles and live near the surface, respire chiefly through the mouth. In A. Oppel (Ed. 2. (2009). The brain of fish functions similarly to the brain of other animals. https://doi.org/10.1007/s00429-014-0705-0. Montgomery, J. C., Windsor, S., & Bassett, D. (2009). https://doi.org/10.1016/j.jphysparis.2008.10.005. In addition to sharks and rays, nearly everything that swims is prey for both animals. [17][18] Shenacanthus vermiformis, which lived 436 million years ago, had thoracic armour plates resembling those of placoderms.[19]. Producing an electric signal is a specialization in the nervous system of some Osteichthyes. ), Biology of sharks and their relatives II (pp. 393434). A spiracle is a small hole found behind each eye. https://doi.org/10.1007/BF00751027. Didier, D. A. Do fishes have nerves in their mouth, tail, or fins? The males of European thornback rays ( Raja clavata) are about 50 cm (20 inches) wide when they reach first maturity, about seven years after birth; females are 60 to 70 cm (24 . A DiI-tracing study of the neural connections of the pineal organ in two elasmobranchs (Scyliorhinus canicula and Raja montagui) suggests a pineal projection to the midbrain GnRH-immunoreactive nucleus. Fishes in the class Chondrichthyes are included in the division Gnathostomata since they have jaws. Maisey, J. G., Miller, R., Pradel, A., Denton, J. S., Bronson, A., & Janvier, P. (2017). Die Parietalorgane. Osteichthyes fish in the gymnotid group, which includes knife fish and electric eels, can produce a shocking electric current using specialized nerve endings. Journal of Fish Biology, 80(5), 20552088. It contains lymphoid and hemopoietic tissue. Chondrichthyes sensory systems are part of the nervous system responsible for receiving external and internal stimuli and translating them into nerve impulses that are transmitted to the central nervous system where they are processed. Class Chondrichthyes " Cartilaginous Fish" Kingdom: Animalia Phylum: Chordata Sub Phylum: Verterbrata Class: Chondrichthyes Vertebrates are grouped based on anatomical and physiological traits. Cartilaginous fish are considered to have evolved from acanthodians.The discovery of Entelognathus and several examinations of acanthodian characteristics indicate that bony fish evolved directly from placoderm like ancestors, while acanthodians represent a paraphyletic assemblage leading to Chondrichthyes. Osteichthyes have a remarkable set of evolutionary tools to help them navigate their environment, detect predators and prey, and defend themselves in a diverse undersea world. https://doi.org/10.1002/jmor.20106. Chondrichthyes is subdivided into two subclasses: Elasmobranchii- Sharks and rays, skates, sawfishes. Sensory biology of elasmobranchs. Chondrichthyes' sensory systems are part of the nervous system responsible for receiving external and internal stimuli and translating them into nerve impulses that are transmitted to the central nervous system where they are processed. https://doi.org/10.1111/jfb.14068. https://doi.org/10.1023/A:1007647924559. Circulatory System Part 2: The Heart and Major Vessels; Circulatory System Part 3: Blood Pressure; Circulatory System Part 4: Vessels, Capillary Fluid Exchange, Lymphatic System; Unit 7: Respiratory System. American Museum of Natural History Novitates, 3119, 186. Electroreception in marine fishes: Chondrichthyans. Brown, B. R. (2003). PubMed 2, pp. Folds of membrane on the roof and floor of the mouth prevent the water from passing down the throat and direct it to the gill openings. Hart, N. S. (2020). Boca Raton: CRC Press. Protected by the shell and nourished by the abundant yolk, the embryo of an oviparous species develops for 18 to 59 weeks before hatching. With the mouth closed, they contract the bucco-pharyngeal cavity while dilating the gill pouches, thus drawing the water over the gills where the exchange of oxygen and carbon dioxide takes place. Question: Why would a shark a free swimming fish want to produce a lot of oil? A., & Demski, L. S. (2004). https://doi.org/10.1206/3875.1. Newton, K. C., Gill, A. https://doi.org/10.1242/jeb.01140. The pineal organ of Raja clavata: Opsin immunoreactivity and ultrastructure. These can be tiny and circular, such as found on the nurse shark (Ginglymostoma cirratum), to extended and slit-like, such as found on the wobbegongs (Orectolobidae). The nervous system is composed of neural tissue which works by reacting to stimuli and sending responses via electric signals. To unlock this lesson you must be a Study.com Member. It also contains the cerebrum, which plays an important role in olfactory processes. It is possible for them to be oviparous, viviparous, or ovoviviparous. Alternative life-history styles of cartilaginous fishes in time and space. Google Scholar. Each clasper has a groove for guidance of sperm. All species of sharks, rays, and chimaeras produce large yolk-rich eggs. The forebrain connects to the midbrain by the diencephalon, a hormone-balancing structure. https://doi.org/10.1002/jmor.1068. Chondrichthyes digestive system: The stomach, pharynx, mouth, intestines, and cloaca make up the digestive system. Fish brain anatomy is often divided into four separate components: Anatomy of the fish brain and spinal cord. https://doi.org/10.1038/421495a. At the rostral, or nose, end of the fish lie olfactory lobes, which provide the sense of smell. Alternative life-history styles of cartilaginous fishes in time and space. Part of Springer Nature. In the next five years it grows about 60 mm (about 2.4 inches) more toward its maximum recorded width of 25 cm (10 inches) in males or 31 cm (12.25 inches) in females. Having skeletons predominantly composed of cartilage is characteristic of cartilaginous fish, while having skeletons mostly composed of bone is characteristic of bony fish. Head morphology and pore distribution of carcharhinid and sphyrnid sharks. The Greenland shark (Somniosus microcephalus), which attains 6.5 metres (21 feet) or more (although rarely taken larger than about 4 metres [13 feet]), grows only about 7.5 mm (about 0.3 inch) per year. The cerebellum helps fishes maintain equilibrium, while the brain stem connects the spinal cord to the brain and coordinates sensory information. Environmental Biology of Fishes, 60(13), 4775. Hueter, R. E., Mann, D. A., Maruska, K. P., Sisneros, J. Chondrichthyes' sensory systems are part of the nervous system responsible for receiving external and internal stimuli and translating them into nerve impulses that are transmitted to the central nervous system where they are processed. 5. https://doi.org/10.1111/j.1095-8649.2011.03214.x. Carrier, J. Musick, & M. Heithaus (Eds. List of transitional fossils Chondrichthyes, Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date, "Function of the heterocercal tail in sharks: quantitative wake dynamics during steady horizontal swimming and vertical maneuvering", "Origin and evolution of the adaptive immune system: genetic events and selective pressures", "Sharks, rays and abortion: The prevalence of capture-induced parturition in elasmobranchs", "The diplacanthid fishes (Acanthodii, Diplacanthiformes, Diplacanthidae) from the Middle Devonian of Scotland", "Chondrichthyan-like scales from the Middle Ordovician of Australia", "The systematics of the Mongolepidida (Chondrichthyes) and the Ordovician origins of the clade", "Spiny chondrichthyan from the lower Silurian of South China", The oldest complete jawed vertebrates from the early Silurian of China - PubMed, "Jaws for a spiral-tooth whorl: CT images reveal novel adaptation and phylogeny in fossil Helicoprion", Images of many sharks, skates and rays on Morphbank, Myliobatiformes (stingrays and relatives), https://en.wikipedia.org/w/index.php?title=Chondrichthyes&oldid=1142043818, Short description is different from Wikidata, Articles with specifically marked weasel-worded phrases from August 2018, Creative Commons Attribution-ShareAlike License 3.0, This page was last edited on 28 February 2023, at 05:49.
Road Closures In Huntsville, Al Today,
Tameside Council Hardship Payments,
Why Are There No Waves In Panama City Beach,
Ronnie Hillman Car Accident,
Amanda Raye Reed,
Articles C