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61-532: Saltriovenator (meaning " Saltrio hunter") is a genus of ceratosaurian dinosaur that lived during the Sinemurian stage of the Early Jurassic in what is now Italy . The type and only species is Saltriovenator zanellai ; in the past, the species had been known under the informal name "saltriosaur". Although a full skeleton has not yet been discovered, Saltriovenator is thought to have been

122-410: A venator is also a type of Roman gladiator . The specific name honours Zanella. Because the article was published in an electronic publication , Life Science Identifiers were necessary to make the name valid. These are 8C9F3B56-F622-4C39-8E8B-C2E890811E74 for the genus and BDD366A7-6A9D-4A32-9841-F7273D8CA00B for the species. Saltriovenator is the third dinosaur named from Italy, the first from

183-883: A wishbone may support its placement as a tetanuran, although wishbones have been reported from coelophysoids. The 2018 description paper ran a large phylogenetic analysis, and found it to be a basal ceratosaur , the sister-taxon of Berberosaurus . The phylogenetic analysis is as shown: Ornithischia Sauropodomorpha Herrerasauridae Eodromaeus Buriolestes Dracoraptor Coelophysoidea (incl. Liliensternus and Zupaysaurus ) Sarcosaurus Cryolophosaurus Dilophosaurus Sinosaurus Berberosaurus Saltriovenator Genyodectes Ceratosaurus Eoabelisaurus Elaphrosaurus Austrocheirus MNN TIG6 Limusaurus Masiakasaurus Noasaurus Abelisauroidea Szechuanosaurus Xuanhanosaurus Megalosauroidea Allosauroidea Coelurosauria Saltriovenator

244-427: A crown consisting of a cup-like central body known as the theca, and a set of five rays or arms, usually branched and feathery. The mouth and anus are both located on the upper side of the theca, making the dorsal (upper) surface the oral surface, unlike in the other echinoderm groups such as the sea urchins , starfish and brittle stars where the mouth is on the underside. The numerous calcareous plates make up

305-402: A few cirri at the base of the crown. The majority of living crinoids are free-swimming and have only a vestigial stalk. In those deep-sea species that still retain a stalk, it may reach up to 1 m (3 ft) in length (although usually much smaller), and fossil species are known with 20 m (66 ft) stems. The theca is pentamerous (has five-part symmetry) and is homologous with

366-462: A few, they are located in the arms. Not all the pinnules are reproductive, just those closest to the crown. The gametes are produced in genital canals enclosed in genital coeloms. The pinnules eventually rupture to release the sperm and eggs into the surrounding sea water. In certain genera, such as Antedon , the fertilised eggs are cemented to the arms with secretions from epidermal glands; in others, especially cold water species from Antarctica,

427-450: A hip height of 220 centimetres and a skull length of eighty centimetres. The thighbone length would then have been about eighty to eighty-seven centimetres, which indicates a body weight of 1160 to 1524 kilogrammes. Another method consisted in extrapolating from the known length of the forelimb. Applying the usual limb ratio indicated a hindlimb length of 198 centimetres. The thighbone would then have been 822 to 887 millimetres long, indicating

488-585: A large, bipedal carnivore similar to Ceratosaurus . On 4 August 1996, the first remains of Saltriovenator were discovered by amateur paleontologist Angelo Zanella, searching for ammonites in the Salnova marble quarry in Saltrio , northern Italy. Zanella had already been working for the Museo Civico di Storia Naturale di Milano and this institution after being informed sent out a team to investigate

549-560: A predator. In 2005, a stalked crinoid was recorded pulling itself along the sea floor off the Grand Bahama Island . While it has been known that stalked crinoids could move, before this recording the fastest motion known for a stalked crinoid was 0.6 metres (2 feet) per hour. The 2005 recording showed one of these moving across the seabed at the much faster rate of 4 to 5 cm (1.6 to 2.0 in) per second, or 144 to 180 m (472 to 591 ft) per hour. If one ignores

610-410: A short oesophagus . There is no true stomach, so the oesophagus connects directly to the intestine , which runs in a single loop right around the inside of the calyx. The intestine often includes numerous diverticulae , some of which may be long or branched. The end of the intestine opens into a short muscular rectum . This ascends towards the anus , which projects from a small conical protuberance at

671-483: A surviving clade that went through a bottleneck after the Permian extinction , at that time losing the feeding larval stage. The larva's free-swimming period lasts for only a few days before it settles on the bottom and attaches itself to the underlying surface using an adhesive gland on its underside. The larva then undergoes an extended period of metamorphoses into a stalked juvenile , becoming radially symmetric in

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732-536: A weight of 1269 to 1622 kilogrammes. The precise systematic position of Saltriovenator has been traditionally uncertain, but it is known to be a theropod . Dal Sasso originally referred it to the Tetanurae He later considered that it may represent an allosauroid , although in either case it would predate other members of the clades by roughly 20-30 million years. Benson considered it a member of Coelophysoidea in his review of Magnosaurus . The presence of

793-399: Is not connected to external sea water via a madreporite , as in other echinoderms, but only connected through a large number of pores to the coelom (body cavity). The main fluid reservoir is the muscular-walled ring canal which is connected to the coelom by stone canals lined with calcareous material. The coelom is divided into a number of interconnecting spaces by mesenteries . It surrounds

854-407: Is the only one homologous with the nervous systems of other echinoderms. It consists of a central nerve ring surrounding the mouth, and radial nerves branching into the arms and is sensory in function. Below this lies an intermediate nerve ring, giving off radial nerves supplying the arms and pinnules. These nerves are motor in nature, and control the musculature of the tube feet. The third portion of

915-664: The Moltrasio Formation . The plants have been recovered between the locations of Cellina and Arolo (eastern side of Lake Maggiore), from rocks that have been found to be coeval in age to the Saltrio Formation . The Flora includes genera such as Bennettitales ( Ptilophyllum ), terrestrial Araucariaceae ( Pagiophyllum ), and Cheirolepidiaceae ( Brachyphyllum ), that developed on inland areas with dry-warm conditions. Saltriovenator probably come from this nearby landmass, as other emerged zones, such as

976-410: The phylum Echinodermata , which also includes the starfish , brittle stars , sea urchins and sea cucumbers . They live in both shallow water and in depths of over 9,000 metres (30,000 ft). Adult crinoids are characterised by having the mouth located on the upper surface. This is surrounded by feeding arms, and is linked to a U-shaped gut, with the anus being located on the oral disc near

1037-451: The Alps and the second theropod from Italy, after Scipionyx . The holotype , MSNM V3664 , was found in a layer of the Saltrio Formation dating from the earliest early Sinemurian , 199 million years old. It consists of a fragmentary skeleton with a lower jaw. About 10% of the skeleton has been discovered, including a tooth, a right splenial, a right prearticular, a neck rib, fragments of

1098-463: The Paleozoic. Some fossil crinoids, such as Pentacrinites , seem to have lived attached to floating driftwood and complete colonies are often found. Sometimes this driftwood would become waterlogged and sink to the bottom, taking the attached crinoids with it. The stem of Pentacrinites can be several metres long. Modern relatives of Pentacrinites live in gentle currents attached to rocks by

1159-499: The Province of Varese is a stub . You can help Misplaced Pages by expanding it . Crinoid Crinoids are marine invertebrates that make up the class Crinoidea . Crinoids that remain attached to the sea floor by a stalk in their adult form are commonly called sea lilies , while the unstalked forms, called feather stars or comatulids , are members of the largest crinoid order , Comatulida . Crinoids are echinoderms in

1220-466: The Saltrio formation, on Switzerland ). This was an emerged structural high close to the Saltrio Formation , that caused a division between two near subsiding basins located at Mt. Nudo (East) and Mt. Generoso (West). It settled over a carbonate platform linked with other wider areas that appear along the west to the southeast, developing a large shallow water gulf to the north, where the strata deposited

1281-467: The Trento Platform where it's far of the location of discovery. If so, this theropod was probably the largest predator on the region. [REDACTED] [REDACTED] [REDACTED] [REDACTED] [REDACTED] Saltrio Saltrio borders the following municipalities: Arzo (Switzerland), Clivio , Meride (Switzerland), Viggiù . This article on a location in

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1342-399: The aboral ones, and this is the main means of transport of nutrients and waste products. There is no heart and separate circulatory system but at the base of the disc there is a large blood vessel known as the axial organ, containing some slender blind-ended tubes of unknown function, which extends into the stalk. These various fluid-filled spaces, in addition to transporting nutrients around

1403-411: The arms in three groups. At first the direction of travel is upwards but soon becomes horizontal, travelling at about 7 cm (2.8 in) per second with the oral surface in front. Swimming usually takes place as short bursts of activity lasting up to half a minute, and in the comatulid Florometra serratissima at least, only takes place after mechanical stimulation or as an escape response evoked by

1464-520: The beginning of the Jurassic, from Hettangian to earliest Sinemurian on the western Lombardy Basin there was a notorious continental area that was found to be wider than previously thought, where a warm humid paleoclimate developed. The Dinosaur Fossils found on the Saltrio formation could have been translated from this area, or alternatively, the Arbostora swell (that was located at the north of

1525-413: The body or disc of other echinoderms. The base of the theca is formed from a cup-shaped set of ossicles (bony plates), the calyx , while the upper surface is formed by the weakly-calcified tegmen , a membranous disc. The tegmen is divided into five "ambulacral areas", including a deep groove from which the tube feet project, and five "interambulacral areas" between them. The mouth is near the centre or on

1586-482: The body, also function as both a respiratory and an excretory system. Oxygen is absorbed primarily through the tube feet, which are the most thin-walled parts of the body, with further gas exchange taking place over the large surface area of the arms. There are no specialised organs for excretion while waste is collected by phagocytic coelomocytes. The crinoid nervous system is divided into three parts, with numerous connections between them. The oral or uppermost portion

1647-495: The bones. Initially, 119 bone fragments were reported to have been collected in total; this was later increased to 132. However, most cannot be exactly identified. In 2000, the museum opened a special exhibition of the bones. On this occasion, Dal Sasso provisionally gave the dinosaur, now thought to be a species new to science, the Italian name Saltriosauro . Although this has been occasionally Latinised to "Saltriosaurus", even in

1708-469: The bulk of the crinoid, with only a small percentage of soft tissue. These ossicles fossilise well and there are beds of limestone dating from the Lower Carboniferous around Clitheroe , England, formed almost exclusively from a diverse fauna of crinoid fossils. The stem of sea lilies is composed of a column of highly porous ossicles which are connected by ligamentary tissue. It attaches to

1769-433: The carcass was subject to scavenging by marine invertebrates. The specimen represents a subadult individual, nearing its maximum size, of which the age has been estimated at twenty-four years. Because of the fragmentary nature of the remains, it was impossible to directly measure the size of the animal. The describing authors therefore compared the fossils with those of two theropods of a roughly similar volume. Comparing with

1830-541: The cilia propel the mucus and food particles towards the mouth. Lappets at the side of the groove help keep the mucus stream in place. The total length of the food-trapping surface may be very large; the 56 arms of a Japanese sea lily with 24 cm (9 in) arms, have a total length of 80 m (260 ft) including the pinnules. Generally speaking, crinoids living in environments with relatively little plankton have longer and more highly branched arms than those living in food-rich environments. The mouth descends into

1891-494: The class was much more abundant and diverse in the past. Some thick limestone beds dating to the mid- Paleozoic era to Jurassic period are almost entirely made up of disarticulated crinoid fragments. The name "Crinoidea" comes from the Ancient Greek word κρίνον ( krínon ), "a lily", with the suffix –oid meaning "like". The basic body form of a crinoid is a stem (not present in adult feather stars) and

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1952-419: The course of a few weeks. The stalk's uppermost segment and the basal plates have the capacity to regenerate the entire crown. Nutrients and other components from the stalk, especially the upper 5 cm, are used in crown regeneration. Crinoids have been able to regenerate parts since Paleozoic times. These regenerative abilities may be vital in surviving attacks by predatory fish. Most modern crinoids, i.e.,

2013-686: The crinoids, and that the crinoids flee, offering part of their stem in the process. Various crinoid fossils hint at possible prehistoric predators. Coprolites of both fish and cephalopods have been found containing ossicles of various crinoids, such as the pelagic crinoid Saccocoma , from the Jurassic lagerstatten Solnhofen , while damaged crinoid stems with bite marks matching the toothplates of coccosteid placoderms have been found in Late Devonian Poland . The calyxes of several Devonian to Carboniferous -aged crinoids have

2074-467: The dorsal ribs and scapulae , a well preserved but incomplete furcula , humeri , metacarpal II, phalanx II-1, phalanx III-1, phalanx III-2, manual ungual III, a distal tarsal III, a distal tarsal IV and the proximal second to fifth metatarsals. The holotype individual likely died on the shores of an ancient beach before being washed out to sea. After death, the skeletal remains suffered from prolonged transport, during which many bones were lost and

2135-599: The edge of the tegmen. Faecal matter is formed into large, mucous-cemented pellets which fall onto the tegmen and thence the substrate. Specimens of the sea urchin Calocidaris micans found in the vicinity of the crinoid Endoxocrinus parrae , have been shown to contain large quantities of stem portions in their guts. These consist of articulated ossicles with soft tissue, whereas the local sediment contained only disarticulated ossicles without soft tissue. This makes it highly likely that these sea urchins are predators of

2196-471: The eggs are brooded in specialised sacs on the arms or pinnules. The fertilised eggs hatch to release free-swimming vitellaria larvae . The bilaterally symmetrical larva is barrel-shaped with rings of cilia running round the body, and a tuft of sensory hairs at the upper pole. While both feeding (planktotrophic) and non-feeding (lecithotrophic) larvae exist among the four other extant echinoderm classes, all present day crinoids appear to be descendants from

2257-452: The end of their stem. In 2012, three geologists reported they had isolated complex organic molecules from 340-million-year-old ( Mississippian ) fossils of multiple species of crinoids. Identified as "resembl[ing ...] aromatic or polyaromatic quinones ", these are the oldest molecules to be definitively associated with particular individual fossils, as they are believed to have been sealed inside ossicle pores by precipitated calcite during

2318-527: The enigmatic Echmatocrinus of the Burgess Shale , the earliest known unequivocal crinoid groups date back to the Ordovician , 480 million years ago. There are two competing hypotheses pertaining to the origin of the group: the traditional viewpoint holds that crinoids evolved from within the blastozoans (the eocrinoids and their derived descendants, the blastoids and the cystoids ), whereas

2379-548: The feather stars, are free-moving and lack a stem as adults. Examples of fossil crinoids that have been interpreted as free-swimming include Marsupites , Saccocoma and Uintacrinus . In general, crinoids move to new locations by crawling, using the cirri as legs. Such a movement may be induced in relation to a change in current direction, the need to climb to an elevated perch to feed, or because of an agonistic behaviour by an encountered individual. Crinoids can also swim. They do this by co-ordinated, repeated sequential movements of

2440-498: The find. Cristiano Dal Sasso and the volunteers of the Paleontological Group of Besano, under the direction of Giorgio Teruzzi managed to salvage a number of chalk blocks visibly containing bones. The skeleton had shortly before its discovery been blown to pieces by explosives used in the quarry to break the marble layers. Blocks that had been secured were inserted into a bath of formic acid for 1,800 hours to free

2501-518: The first during the Ordovician (485 to 444 mya), and the other during the early Triassic (around 230 mya). This Triassic radiation resulted in forms possessing flexible arms becoming widespread; motility , predominantly a response to predation pressure, also became far more prevalent than sessility. This radiation occurred somewhat earlier than the Mesozoic marine revolution , possibly because it

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2562-525: The fossilization process. Crinoid fossils, and in particular disarticulated crinoid columnals, can be so abundant that they at times serve as the primary supporting clasts in sedimentary rocks. Rocks of this nature are called encrinites . Crinoidea has been accepted as a distinct clade of echinoderms since the definition of the group by Miller in 1821. It includes many extinct orders as well as four closely related living orders ( Comatulida , Cyrtocrinida , Hyocrinida , and Isocrinida ), which are part of

2623-586: The free-swimming feather stars, the arms branch several more times, producing up to two hundred branches in total. Being jointed, the arms can curl up. They are lined, on either side alternately, by smaller jointed appendages known as "pinnules" which give them their feather-like appearance. Both arms and pinnules have tube feet along the margins of the ambulacral grooves. The tube feet come in groups of three of different size; they have no suction pads and are used to hold and manipulate food particles. The grooves are equipped with cilia which facilitate feeding by moving

2684-538: The margin of the tegmen, and ambulacral grooves lead from the base of the arms to the mouth. The anus is also located on the tegmen, often on a small elevated cone, in an interambulacral area. The theca is relatively small and contains the crinoid's digestive organs. The arms are supported by a series of articulating ossicles similar to those in the stalk. Primitively, crinoids had only five arms, but in most modern forms these are divided into two at ossicle II, giving ten arms in total. In most living species, especially

2745-421: The most popular alternative suggests that the crinoids split early from among the edrioasteroids . The debate is difficult to settle, in part because all three candidate ancestors share many characteristics, including radial symmetry, calcareous plates, and stalked or direct attachment to the substrate. Echinoderms with mineralized skeletons entered the fossil record in the early Cambrian (540 mya), and during

2806-494: The mouth. Although the basic echinoderm pattern of fivefold symmetry can be recognised, in most crinoids the five arms are subdivided into ten or more. These have feathery pinnules and are spread wide to gather planktonic particles from the water. At some stage in their lives, most crinoids have a short stem used to attach themselves to the substrate , but many live attached only as juveniles and become free-swimming as adults. There are only about 700 living species of crinoid, but

2867-410: The nervous system lies aborally, and is responsible for the flexing and movement actions of the arms, pinnules and cirri. This is centred on a mass of neural tissue near the base of the calyx, and provides a single nerve to each arm and a number of nerves to the stalk. Crinoids are dioecious , with individuals being either male or female. In most species, the gonads are located in the pinnules but in

2928-497: The next 100 million years, the crinoids and blastoids (also stalked filter-feeders) were dominant. At that time, the Echinodermata included twenty taxa of class rank, only five of which survived the mass extinction events that followed. The long and varied geological history of the crinoids demonstrates how well the echinoderms had adapted to filter-feeding. The crinoids underwent two periods of abrupt adaptive radiation ,

2989-452: The organic particles along the arm and into the mouth. Crinoids are passive suspension feeders , filtering plankton and small particles of detritus from the sea water flowing past them with their feather-like arms. The arms are raised to form a fan-shape which is held perpendicular to the current. Mobile crinoids move to perch on rocks, coral heads or other eminences to maximise their feeding opportunities. The food particles are caught by

3050-413: The primary (longest) tube feet, which are fully extended and held erect from the pinnules, forming a food-trapping mesh, while the secondary and tertiary tube feet are involved in manipulating anything encountered. The tube feet are covered with sticky mucus that traps any particles which come in contact. Once they have caught a particle of food, the tube feet flick it into the ambulacral groove, where

3111-407: The process. Even the free-swimming feather stars go through this stage, with the adult eventually breaking away from the stalk. Crinoids are not capable of clonal reproduction as are some starfish and brittle stars , but are capable of regenerating lost body parts. Arms torn off by predators or damaged by adverse environmental conditions can regrow, and even the visceral mass can regenerate over

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3172-437: The remaining ones highly fragmented. Although Saltriovenator was not aquatic, the environment in which the carcass was deposited was likely pelagic , judging by the associated ammonites . The locality is also rich in crinoids , gastropods , bivalves , brachiopods and bryozoans . Deposition occurred on a slope between a shallow carbonate platform and a deeper basin. Various scratches, grooves, and striations indicate that

3233-401: The scientific literature, in both the Italian and Latin form it remained an invalid nomen nudum . In December 2018, Dal Sasso, Simone Maganuco and Andrea Cau named and described the specimen as the type species Saltriovenator zanellai . The generic name combines a reference to Saltrio with Latin , venator , "hunter", a common suffix in the names of theropods. The authors pointed out that

3294-413: The shells of a snail, Platyceras , intimately associated with them. Some have the snail situated over the anus, suggesting that Platyceras was a coprophagous commensal, while others have the animal directly situated over a borehole, suggesting a more pernicious relationship. Like other echinoderms, crinoids possess a water vascular system that maintains hydraulic pressure in the tube feet. This

3355-542: The skeletal elements of MOR 693, an Allosaurus fragilis specimen, they conservatively concluded that the Saltriovenator holotype individual was at least seven to eight metres long. This would make Saltriovenator the largest known theropod living before the Aalenian stage, 25% longer than Ceratosaurus from the late Jurassic. Comparing with Ceratosaurus itself, resulted in a body length of 730 centimetres,

3416-535: The subgroup Articulata . Living articulates comprise around 540 species. The phylogeny , geologic history, and classification of the Crinoidea was discussed by Wright et al. (2017). These authors presented new phylogeny-based and rank-based classifications based on results of recent phylogenetic analyses. Their rank-based classification of crinoid higher taxa (down to Order), not fully resolved and with numerous groups incertae sedis (of uncertain placement),

3477-421: The substrate with a flattened holdfast or with whorls of jointed, root-like structures known as cirri . Further cirri may occur higher up the stem. In crinoids that attach to hard surfaces, the cirri may be robust and curved, resembling birds' feet, but when crinoids live on soft sediment, the cirri may be slender and rod-like. Juvenile feather stars have a stem, but this is later lost, with many species retaining

3538-427: The viscera in the disc and has branches within the stalk and arms, with smaller branches extending into the pinnules. It is the contraction of the ring canal that extends the tube feet. Three narrow branches of the coelom enter each arm, two on the oral side and one aborally, and pinnules. The action of cilia cause there to be a slow flow of fluid (1mm per second) in these canals, outward in the oral branches and inward in

3599-489: Was controlled by a horst and tectonic gaben. Several outcrops of the so-called "terra rossa" paleosoils were also found, including at Castello Cabiaglio-Orino , a dozen of kilometers West of Saltrio. These outcrops show that the emerged areas that on the Hettangian-Sinemurian, the current location of the modern Maggiore Lake was covered with forests, what was proven by the presence of large plant fragments on

3660-424: Was found on an open marine environment, where it was probably washed from the nearest mainland, being scavenged by invertebrates as proven by the presence of Sedilichnus sp. on the bones. This depositional environment, part of the Saltrio Formation is considered as part of a proximal slope or ramp that was probably an open subtidal zone reached by the effects of storm waves and with constant bottom currents. Since

3721-483: Was mainly prompted by increases in benthic predation, specifically of echinoids. There then followed a selective mass extinction at the end of the Permian period, during which all blastoids and most crinoids became extinct. After the end-Permian extinction, crinoids never regained the morphological diversity and dominant position they enjoyed in the Paleozoic; they employed a different suite of ecological strategies open to them from those that had proven so successful in

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