Elasmobranchii

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Elasmobranchii
Temporal range: Givetian–Recent
Great White Shark (14730719119).jpg
Great white shark
(Carcharodon carcharias)
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Bonaparte, 1838
Subgroups

See text

Cetorhinus maximus by greg skomal.JPG

Elasmobranchs lack swim bladders, and maintain buoyancy with oil that they store in their livers. Some deep sea sharks are targeted by fisheries for this liver oil, including the school, gulper and basking sharks (pictured). [1] All three of these species have been assessed by the IUCN as vulnerable due to overfishing. [2] [3] [4]

Contents

From a practical point of view the life-history pattern of elasmobranchs makes this group of animals extremely susceptible to over fishing. It is no coincidence that the commercially exploited marine turtles and baleen whales, which have life-history patterns similar to the sharks, are also in trouble. [5]

Elasmobranchii ( /ɪˌlæzməˈbræŋkiaɪ/ [6] ) is a subclass of Chondrichthyes or cartilaginous fish, including modern sharks (superorder Selachii), rays, skates, and sawfish (superorder Batoidea). Members of this subclass are characterised by having five to seven pairs of gill slits opening individually to the exterior, rigid dorsal fins and small placoid scales on the skin. The teeth are in several series; the upper jaw is not fused to the cranium, and the lower jaw is articulated with the upper. The details of this jaw anatomy vary between species, and help distinguish the different elasmobranch clades. The pelvic fins in males are modified to create claspers for the transfer of sperm. There is no swim bladder; instead, these fish maintain buoyancy with large livers rich in oil.

The definition of the clade is unclear with respect to fossil chondrichthyans. Some authors consider it as equivalent to Neoselachii (the crown group clade including modern sharks, rays, and all other descendants of their last common ancestor). Other authors use the name Elasmobranchii for a broader branch-based group of all chondrichthyans more closely related to modern sharks and rays than to Holocephali (the clade containing chimaeras and their extinct relatives). [7] Important extinct groups of elasmobranchs sensu lato include the hybodonts (Order Hybodontiformes), xenacanths (order Xenacanthformes) and Ctenacanthiformes. These are also often referred to as "sharks" in reference to their similar anatomy and ecology to modern sharks.

The name Elasmobranchii comes from the Ancient Greek words elasmo- ("plate") and bránchia ("gill"), referring to the broad, flattened gills which are characteristic of these fishes.

Description

Elasmobranchii is one of the two subclasses of cartilaginous fish in the class Chondrichthyes, the other being Holocephali (chimaeras).

Members of the elasmobranchii subclass have no swim bladders, five to seven pairs of gill clefts opening individually to the exterior, rigid dorsal fins, and small placoid scales. The teeth are in several series; the upper jaw is not fused to the cranium, and the lower jaw is articulated with the upper.

Extant elasmobranchs exhibit several archetypal jaw suspensions: amphistyly, orbitostyly, hyostyly, and euhyostyly. In amphistyly, the palatoquadrate has a postorbital articulation with the chondrocranium from which ligaments primarily suspend it anteriorly. The hyoid articulates with the mandibular arch posteriorly, but it appears to provide little support to the upper and lower jaws. In orbitostyly, the orbital process hinges with the orbital wall and the hyoid provides the majority of suspensory support.

In contrast, hyostyly involves an ethmoid articulation between the upper jaw and the cranium, while the hyoid most likely provides vastly more jaw support compared to the anterior ligaments. Finally, in euhyostyly, also known as true hyostyly, the mandibular cartilages lack a ligamentous connection to the cranium. Instead, the hyomandibular cartilages provide the only means of jaw support, while the ceratohyal and basihyal elements articulate with the lower jaw, but are disconnected from the rest of the hyoid. [8] [9] [10] The eyes have a tapetum lucidum. The inner margin of each pelvic fin in the male fish is grooved to constitute a clasper for the transmission of sperm. These fish are widely distributed in tropical and temperate waters. [11]

Many fish maintain buoyancy with swim bladders. However elasmobranchs lack swim bladders, and maintain buoyancy instead with large livers that are full of oil. [12] This stored oil may also function as a nutrient when food is scarce. [5] [13]

Evolutionary history

The oldest unambigous total group elasmobranch, Phoebodus, has its earliest records in the Middle Devonian (late Givetian), around 383 million years ago. [14] Several important groups of total group elasmobranchs, including Ctenacanthiformes and Hybodontiformes, had already emerged by the latest Devonian (Famennian). [15] During the Carboniferous, some ctenacanths would grow to sizes rivalling the modern great white shark with bodies in the region of 7 metres (23 ft) in length. [16] During the Carboniferous and Permian, the xenacanths were abundant in both freshwater and marine environments, and would continue to exist into the Triassic with reduced diversity. [17] The hybodonts had achieved a high diversity by the Permian, [18] and would end up becoming the dominant group of elasmobranchs during the Triassic and Early Jurassic. Hybodonts were extensively present in both marine and freshwater environments. [19] While Neoselachii/Elasmobranchi sensu stricto (the group of modern sharks and rays) had already appeared by the Triassic, they only had low diversity during this period would and only begin to extensively diversify from the Early Jurassic onwards, when modern orders of sharks and rays appeared. [20] This co-incided with the decline of the hybodonts, which had become minor components of marine environments by the Late Jurassic, but would remain common in freshwater environments into the Cretaceous. [21] The youngest remains of hybodonts date to the very end of the Cretaceous. [22]

Taxonomy

Elasmobranchii was first coined in 1838 by Charles Lucien Bonaparte. Bonaparte's original definition of Elasmobranchii was effectively identical to modern Chondrichthyes, and was based around gill architecture shared by all 3 living major cartilaginous fish groups. During the 20th century it became standard to exclude chimaeras from Elasmobranchii; along with including many fossil chondrichthyans within the group. The definition of Elasmobranchii has since been subject to much confusion with regard to fossil chondrichthyans. Maisey (2012) suggested that Elasmobranchii should exclusively be used for the last common ancestor of modern sharks and rays, a grouping which had previously been named Neoselachii by Compagno (1977). [7] Other recent authors have used Elasmobranchii in a broad sense to include all chondrichthyans more closely related to modern sharks and rays than to chimaeras. [14]

The total group of Elasmobranchii includes the Cohort Euselachii Hay, 1902, which groups the Hybodontiformes and a number of other extinct chondrichthyans with Elasmobrachii sensu stricto/Neoselachii, to the exclusion of more primitive total group elasmobranchs, which is supported by a number of shared morphological characters of the skeleton. [23] [24] [25] [26]

The 5th edition of Fishes of the World sets out the following classification of the Elasmobranchs: [29]

Recent molecular studies suggest the Batoidea are not derived selachians as previously thought. Instead, skates and rays are a monophyletic superorder within Elasmobranchii that shares a common ancestor with the selachians. [30] [31]

See also

Related Research Articles

<span class="mw-page-title-main">Chondrichthyes</span> Class of jawed cartilaginous fishes

Chondrichthyes is a class of jawed fish that contains the cartilaginous fish or chondrichthyans, which all have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or bony fish, which have skeletons primarily composed of bone tissue. Chondrichthyes are aquatic vertebrates with paired fins, paired nares, placoid scales, conus arteriosus in the heart, and a lack of opercula and swim bladders. Within the infraphylum Gnathostomata, cartilaginous fishes are distinct from all other jawed vertebrates.

<span class="mw-page-title-main">Hexanchiformes</span> Order of sharks

The Hexanchiformes are a primitive order of sharks, numbering just seven extant species in two families. Fossil sharks that were apparently very similar to modern sevengill species are known from Jurassic specimens.

<span class="mw-page-title-main">Skate (fish)</span> Family of fishes

Skates are cartilaginous fish belonging to the family Rajidae in the superorder Batoidea of rays. More than 150 species have been described, in 17 genera. Softnose skates and pygmy skates were previously treated as subfamilies of Rajidae, but are now considered as distinct families. Alternatively, the name "skate" is used to refer to the entire order of Rajiformes.

<i>Cladoselache</i> Extinct genus of chondrichthyans

Cladoselache is an extinct genus of shark-like chondrichthyan from the Late Devonian (Famennian) of North America. It was similar in body shape to modern lamnid sharks, but was not closely related to lamnids or to any other modern (selachian) shark. As an early chondrichthyan, it had yet to evolve traits of modern sharks such as accelerated tooth replacement, a loose jaw suspension, enameloid teeth, and possibly claspers.

<span class="mw-page-title-main">Rajiformes</span> Order of fishes in the superorder Batoidea

Rajiformes is one of the four orders in the clade Batomorphi, often referred to as the superorder Batoidea, flattened cartilaginous fishes related to sharks. Rajiforms are distinguished by the presence of greatly enlarged pectoral fins, which reach as far forward as the sides of the head, with a generally flattened body. The undulatory pectoral fin motion diagnostic to this taxon is known as rajiform locomotion. The eyes and spiracles are located on the upper surface of the head and the gill slits are on the underside of the body. Most species give birth to live young, although some lay eggs enclosed in a horny capsule.

<i>Stethacanthus</i> Extinct genus of cartilaginous fishes

Stethacanthus is an extinct genus of shark-like cartilaginous fish which lived from the Late Devonian to Late Carboniferous epoch, dying out around 298.9 million years ago. Fossils have been found in Australia, Asia, Europe and North America.

<span class="mw-page-title-main">Xenacanthida</span> Extinct order of cartilaginous fishes

Xenacanthida is an order or superorder of extinct shark-like chondrichthyans known from the Carboniferous to Triassic. They were native to freshwater, marginal marine and shallow marine habitats. Some xenacanths may have grown to lengths of 5 m (16 ft). Most xenacanths died out at the end of the Permian in the End-Permian Mass Extinction, with only a few forms surviving into the Triassic.

<i>Hybodus</i> Extinct genus of shark-like hybodont

Hybodus is an extinct genus of hybodont that lived from the Middle Triassic to the Late Cretaceous periods. Species closely related to the type species Hybodus reticulatus lived during the Early Jurassic epoch. Numerous species have been assigned to Hybodus spanning a large period of time, and it is currently considered a wastebasket taxon that is 'broadly polyphyletic' and requires reexamination.

<i>Tristychius</i> Extinct genus of sharks

Tristychius is an extinct genus of euselachian chondrichthyan from the Carboniferous period (Visean). Fossils of T. arcuatus, the type and only species, including fin spines have been found in Scotland.

<span class="mw-page-title-main">Hybodontiformes</span> Extinct order of chondrichthyans

Hybodontiformes, commonly called hybodonts, are an extinct group of shark-like cartilaginous fish (chondrichthyans) which existed from the late Devonian to the Late Cretaceous. Hybodonts share a close common ancestry with modern sharks and rays (Neoselachii) as part of the clade Euselachii. They are distinguished from other chondrichthyans by their distinctive fin spines and cephalic spines present on the heads of males. An ecologically diverse group, they were abundant in marine and freshwater environments during the late Paleozoic and early Mesozoic, but were rare in open marine environments by the end of the Jurassic, having been largely replaced by modern sharks, though they were still common in freshwater and marginal marine habitats. They survived until the end of the Cretaceous, before going extinct.

<span class="mw-page-title-main">Batomorphi</span> Superorder of cartilaginous fishes

Batomorphi is a clade of cartilaginous fishes, commonly known as rays, this taxon is also known as the superorder Batoidea, but the 5th edition of Fishes of the World classifies it as the division Batomorphi. They and their close relatives, the sharks, compose the subclass Elasmobranchii. Rays are the largest group of cartilaginous fishes, with well over 600 species in 26 families. Rays are distinguished by their flattened bodies, enlarged pectoral fins that are fused to the head, and gill slits that are placed on their ventral surfaces.

<i>Meristodonoides</i> Extinct genus of hybodont chondrichthyans

Meristodonoides is an extinct genus of hybodont known from the mid-late Cretaceous, with potential records dating back to the Jurassic. It is one of a number of hybodont genera composed of species formerly assigned to Hybodus.

<span class="mw-page-title-main">Synechodontiformes</span> Extinct order of sharks

Synechodontiformes is an extinct order of prehistoric shark-like cartilaginous fish, known from the Permian to the Paleogene. They are considered to be members of Neoselachii, the group that contains modern sharks and rays.

<i>Synechodus</i> Fossil genus of cartilaginous fish

Synechodus is an extinct genus of shark belonging to the family Palaeospinacidae and order Synechodontiformes. It is known from 16 species primarily spanning from the Late Triassic to Paleocene. The dentition is multicusped and was used for grasping. Several species are known from skeletal remains, including the species Synechodus ungeri from the Late Jurassic of Germany, which shows that it was relatively short with large pectoral fins and a proportionally large head with a round snout. This species is suggested to have reached a body length of 30–40 centimetres (0.98–1.31 ft). Skeletal remains are also known of the species Synechodus dubrisiensis from the Cretaceous of Europe. A skeleton of an indeterminate species is also known from the Early Cretaceous (Albian) of France, with a body length of around 70 centimetres (2.3 ft). Synechodus is suggested to have had two dorsal fins that lacked fin spines, though the number of dorsal fins is unknown in Synechodus ungeri.

Tribodus is an extinct genus of hybodont. It lived during the mid Cretaceous (Albian-Cenomanian) with fossils being known from northern South America, North Africa, and southern Europe.

<i>Pseudorhina</i> Extinct genus of sharks

Pseudorhina is an extinct genus of squatiniform shark closely related to modern angelsharks. Fossils are known from the Late Jurassic and Early Cretaceous of Europe.

<span class="mw-page-title-main">Ctenacanthiformes</span> Extinct order of cartilaginous fishes

Ctenacanthiformes is an extinct order of cartilaginous fish. They possessed ornamented fin spines at the front of their dorsal fins and cladodont-type dentition, that is typically of a grasping morphology, though some taxa developed cutting and gouging tooth morphologies. Some ctenacanths are thought to have reached sizes comparable to the great white shark, with body lengths of up to 7 metres (23 ft) and weights of 1,500–2,500 kilograms (3,300–5,500 lb), while others reached lengths of only 30 centimetres (12 in). The earliest ctenacanths appeared during the Frasnian stage of the Late Devonian, with the group reaching their greatest diversity during the Early Carboniferous (Mississippian), and continued to exist into at least the Middle Permian (Guadalupian). Some authors have suggested members of the family Ctenacanthidae may have survived into the Cretaceous based on teeth found in deep water deposits of Valanginian age in France and Austria, however, other authors contend that the similarity of these teeth to Paleozoic ctenacanths is only superficial, and they likely belong to neoselachians instead.

Anachronistidae is an extinct family of cartilaginous fish, known from the Carboniferous and Permian periods. They are considered to be the oldest known members of Neoselachii, with a close relationship to modern sharks and rays. Known primarily from isolated teeth, these ancient fish were recorded to first exist in Europe during the late Mississippian epoch. Over time, the genus Cooleyella expanded its range into North America and South America during the Late Carboniferous and continued to exist in the Permian period.

This list of fossil fish research presented in 2024 is a list of new fossil taxa of jawless vertebrates, placoderms, cartilaginous fishes, bony fishes, and other fishes that were described during the year, as well as other significant discoveries and events related to paleoichthyology that occurred in 2024.

References

  1. ↑ Vannuccini, Stefania (2002) Shark liver oil products Archived 2013-06-26 at the Wayback Machine In: Shark Utilization, Marketing and Trade, Fisheries Technical paper 389, FAO, Rome. ISBN   92-5-104361-2.
  2. ↑ Fowler, S.L. (2005). "Cetorhinus maximus". IUCN Red List of Threatened Species . 2005: e.T4292A10763893. doi: 10.2305/IUCN.UK.2005.RLTS.T4292A10763893.en .
  3. ↑ Walker, T.I.; Rigby, C.L.; Pacoureau, N.; Ellis, J.; Kulka, D.W.; Chiaramonte, G.E.; Herman, K. (2020). "Galeorhinus galeus". IUCN Red List of Threatened Species . 2020: e.T39352A2907336. doi: 10.2305/IUCN.UK.2020-2.RLTS.T39352A2907336.en . Retrieved 11 November 2021.[ permanent dead link ]
  4. ↑ Finucci, B.; Bineesh, K.K.; Cheok, J.; Cotton, C.F.; Dharmadi, Kulka, D.W.; Neat, F.C.; Pacoureau, N.; Rigby, C.L.; Tanaka, S.; Walker, T.I. (2020). "Centrophorus granulosus". IUCN Red List of Threatened Species . 2020: e.T162293947A2897883. doi: 10.2305/IUCN.UK.2020-3.RLTS.T162293947A2897883.en . Retrieved 11 November 2021.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  5. 1 2 Hoenig, J.M. and Gruber, S.H. (1990) "Life-history patterns in the elasmobranchs: implications for fisheries management" Archived 2013-02-18 at the Wayback Machine In: Elasmobranchs as living resources: advances in the biology, ecology, systematics and the status of the fisheries, eds. J. H. L. Pratt, S. H. Gruber and T. Taniuchi, US Department of Commerce, NOAA technical report NMFS 90, pp.1–16.
  6. ↑ "Elasmobranch". Merriam-Webster.com Dictionary . Merriam-Webster.
  7. 1 2 Maisey, J. G. (April 2012). "What is an 'elasmobranch'? The impact of palaeontology in understanding elasmobranch phylogeny and evolution". Journal of Fish Biology. 80 (5): 918–951. Bibcode:2012JFBio..80..918M. doi:10.1111/j.1095-8649.2012.03245.x. PMID   22497368.
  8. ↑ Wilga, C.D. (2005). "Morphology and evolution of the jaw suspension in lamniform sharks". Journal of Morphology. 265 (1): 102–19. doi:10.1002/jmor.10342. PMID   15880740. S2CID   45227734.
  9. ↑ Wilga, C. D.; Motta, P. J.; Sanford, C. P. (2007). "Evolution and ecology of feeding in elasmobranchs". Integrative and Comparative Biology. 47 (1): 55–69. doi: 10.1093/icb/icm029 . PMID   21672820.
  10. ↑ Wilga, Cheryl A.D. (2008). "Evolutionary divergence in the feeding mechanism of fishes". Acta Geologica Polonica. 58 (2): 113–20. Archived from the original on 2018-08-19. Retrieved 2017-05-24.
  11. ↑ Bigelow, Henry B.; Schroeder, William C. (1948). Fishes of the Western North Atlantic. Sears Foundation for Marine Research, Yale University. pp. 64–65. ASIN   B000J0D9X6.
  12. ↑ Oguri, M (1990) "A review of selected physiological characteristics unique to elasmobranchs" Archived 2013-02-18 at the Wayback Machine In: Elasmobranchs as living resources: advances in the biology, ecology, systematics and the status of the fisheries, eds. J. H. L. Pratt, S. H. Gruber and T. Taniuchi, US Department of Commerce, NOAA technical report NMFS 90, pp.49–54.
  13. ↑ Bone, Q.; Roberts, B. L. (2009). "The density of elasmobranchs". Journal of the Marine Biological Association of the United Kingdom. 49 (4): 913. doi:10.1017/S0025315400038017. S2CID   85871565.
  14. 1 2 Frey, Linda; Coates, Michael; Ginter, Michał; Hairapetian, Vachik; Rücklin, Martin; Jerjen, Iwan; Klug, Christian (2019-10-09). "The early elasmobranch Phoebodus : phylogenetic relationships, ecomorphology and a new time-scale for shark evolution". Proceedings of the Royal Society B: Biological Sciences. 286 (1912): 20191336. doi:10.1098/rspb.2019.1336. ISSN   0962-8452. PMC   6790773 . PMID   31575362.
  15. ↑ Schultze, H.-P., Bullecks, J., Soar, L. K., & Hagadorn, J. (2021). Devonian fish from Colorado’s Dyer Formation and the appearance of Carboniferous faunas in the Famennian. In A. Pradel, J. S. S. Denton, & P. Janvier (Eds.), Ancient Fishes and their Living Relatives: a Tribute to John G. Maisey (pp. 247–256.). Verlag Dr. Friedrich Pfeil.
  16. ↑ Maisey, John G.; Bronson, Allison W.; Williams, Robert R.; McKinzie, Mark (2017-05-04). "A Pennsylvanian 'supershark' from Texas". Journal of Vertebrate Paleontology. 37 (3): e1325369. Bibcode:2017JVPal..37E5369M. doi:10.1080/02724634.2017.1325369. ISSN   0272-4634. S2CID   134127771.
  17. ↑ Pauliv, Victor E.; Martinelli, Agustín G.; Francischini, Heitor; Dentzien-Dias, Paula; Soares, Marina B.; Schultz, Cesar L.; Ribeiro, Ana M. (December 2017). "The first Western Gondwanan species of Triodus Jordan 1849: A new Xenacanthiformes (Chondrichthyes) from the late Paleozoic of Southern Brazil". Journal of South American Earth Sciences. 80: 482–493. Bibcode:2017JSAES..80..482P. doi:10.1016/j.jsames.2017.09.007.
  18. ↑ Koot, Martha B.; Cuny, Gilles; Tintori, Andrea; Twitchett, Richard J. (March 2013). "A new diverse shark fauna from the Wordian (Middle Permian) Khuff Formation in the interior Haushi-Huqf area, Sultanate of Oman". Palaeontology. 56 (2): 303–343. Bibcode:2013Palgy..56..303K. doi:10.1111/j.1475-4983.2012.01199.x. ISSN   0031-0239. S2CID   86428264.
  19. ↑ Rees, J. A. N., and Underwood, C. J., 2008, Hybodont sharks of the English Bathonian and Callovian (Middle Jurassic): Palaeontology, v. 51, no. 1, p. 117–147.
  20. ↑ Underwood, Charlie J. (March 2006). "Diversification of the Neoselachii (Chondrichthyes) during the Jurassic and Cretaceous". Paleobiology. 32 (2): 215–235. Bibcode:2006Pbio...32..215U. doi:10.1666/04069.1. ISSN   0094-8373. S2CID   86232401.
  21. ↑ Rees, Jan; Underwood, Charlie J. (January 2008). "Hybodont Sharks of the English Bathonian and Callovian (Middle Jurassic)". Palaeontology. 51 (1): 117–147. Bibcode:2008Palgy..51..117R. doi: 10.1111/j.1475-4983.2007.00737.x . ISSN   0031-0239.
  22. ↑ Carrillo-Briceño, Jorge D.; Cadena, Edwin A.; Dececchi, Alex T.; Larson, Hans C. E.; Du, Trina Y. (2016-01-01). "First record of a hybodont shark (Chondrichthyes: Hybodontiformes) from the Lower Cretaceous of Colombia". Neotropical Biodiversity. 2 (1): 81–86. Bibcode:2016NeBio...2...81C. doi:10.1080/23766808.2016.1191749. ISSN   2376-6808.
  23. ↑ Maisey, John G. (March 2011). "The braincase of the Middle Triassic shark Acronemus tuberculatus (Bassani, 1886)". Palaeontology. 54 (2): 417–428. Bibcode:2011Palgy..54..417M. doi:10.1111/j.1475-4983.2011.01035.x. ISSN   0031-0239. S2CID   140697673.
  24. ↑ Coates, Michael I.; Tietjen, Kristen (March 2017). "The neurocranium of the Lower Carboniferous shark Tristychius arcuatus (Agassiz, )". Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 108 (1): 19–35. Bibcode:2017EESTR.108...19C. doi:10.1017/S1755691018000130. ISSN   1755-6910. S2CID   135297534.
  25. ↑ Villalobos-Segura, Eduardo; Stumpf, Sebastian; Türtscher, Julia; Jambura, Patrick; Begat, Arnaud; López-Romero, Faviel; Fischer, Jan; Kriwet, Jürgen (2023-03-08). "A Synoptic Review of the Cartilaginous Fishes (Chondrichthyes: Holocephali, Elasmobranchii) from the Upper Jurassic Konservat-Lagerstätten of Southern Germany: Taxonomy, Diversity, and Faunal Relationships". Diversity. 15 (3): 386. doi: 10.3390/d15030386 . ISSN   1424-2818. PMC   7614348 . PMID   36950327.
  26. ↑ Luccisano, Vincent; Rambert-Natsuaki, Mizuki; Cuny, Gilles; Amiot, Romain; Pouillon, Jean-Marc; Pradel, Alan (2021-12-02). "Phylogenetic implications of the systematic reassessment of Xenacanthiformes and 'Ctenacanthiformes' (Chondrichthyes) neurocrania from the Carboniferous–Permian Autun Basin (France)". Journal of Systematic Palaeontology. 19 (23): 1623–1642. Bibcode:2021JSPal..19.1623L. doi:10.1080/14772019.2022.2073279. ISSN   1477-2019.
  27. ↑ Ebert, David A.; Fowler, Sarah; Dando, Marc (2021). Sharks of the world: a complete guide. Princeton: Princeton University Press. ISBN   978-0-691-20599-1.
  28. ↑ "WoRMS - World Register of Marine Species - Echinorhiniformes" . Retrieved 2022-01-04.
  29. ↑ Nelson, J.S.; Grande, T.C.; Wilson, M.V.H. (2016). Fishes of the World (5th ed.). Hoboken, NJ: John Wiley & Sons. p. 56. doi:10.1002/9781119174844. ISBN   978-1-118-34233-6. LCCN   2015037522. OCLC   951899884. OL   25909650M.
  30. ↑ Winchell, Christopher J; Martin, Andrew P; Mallatt, Jon (2004). "Phylogeny of elasmobranchs based on LSU and SSU ribosomal RNA genes". Molecular Phylogenetics and Evolution. 31 (1): 214–24. doi:10.1016/j.ympev.2003.07.010. PMID   15019621.
  31. ↑ Douady, Christophe J.; Dosay, Miné; Shivji, Mahmood S.; Stanhope, Michael J. (2003). "Molecular phylogenetic evidence refuting the hypothesis of Batoidea (rays and skates) as derived sharks". Molecular Phylogenetics and Evolution. 26 (2): 215–21. doi:10.1016/S1055-7903(02)00333-0. PMID   12565032.
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