Dec 1, 2017 · It is not surprising, then, that the shell interior of many pelecypod species and genera is still unknown. The microscope, now considered as essential equipment of the paleontologist, has been used only too infrequently in past studies of pelecypod shells, with the result that one whole line of evidence for classification has been neglected ... The Blue-and-Gold Snapper is found aggregations over rocky bottoms and coral reefs at depths up to 55 m (180 feet). They reach a maximum of 30 cm (12 inches) in length. They are nocturnal predators feeding on crabs, mollusks, octopus, shrimp, and small fish and take shelter during daylight.The location of the state of Tennessee. Paleontology in Tennessee refers to paleontological research occurring within or conducted by people from the U.S. state of Tennessee. During the early part of the Paleozoic era, Tennessee was covered by a warm, shallow sea. This sea was home to brachiopods, bryozoans, cephalopods, corals, and …True/False: Horse conchs can grow to 2 feet long. False. True/False: Goose barnacles are mollusks. False. Study with Quizlet and memorize flashcards containing terms like A membrane called the _____ lines the inside of bivalve shells., Mollusks shells are hard due to the presence of the chemical compound _____., The term bivalves means ...Compositional reef types include microbial reefs, sponge reefs, coral reefs, dasycladacean algal reefs, pelecypod reefs, and serpulid reefs. The end-Permian extinction event resulted in the sudden disappearance of high-diversity Late Permian reefs in southern China and a global gap of inetazoan reefs in the Early Triassic and Early Anisian ...Fucus, genus of brown algae, common on rocky seacoasts and in salt marshes of northern temperate regions. Fucus species, along with other kelp, are an important source of alginates—colloidal extracts with many industrial uses similar to those of agar. Bladder wrack (F. vesiculosus) was one of the.The Taxation Incentives for the Arts Scheme in 1987 saw the donation of a magnificent large collection of superb boulder opal specimens and cabochons from Quilpie, Queensland, as well as a large polished opal cabochon, the ‘Desert Beauty’ of 290 carats, fashioned from an opalised pelecypod shell from Coober Pedy, South Australia.Trochophore. A trochophore ( / ˈtroʊkəˌfɔːr, ˈtrɒ -, - koʊ -/; [1] [2]) is a type of free-swimming planktonic marine larva with several bands of cilia . By moving their cilia rapidly, they make a water eddy to control their movement, and to bring their food closer in order to capture it more easily.Request PDF | Pelecypoda | The name "Bivalve" was first coined by Linnaeus in 1758 (later known as "Carl von Linné"; see Bonnani 1681). "Pelecypoda" and "Lamellibranchia ...Fordilla troyensis Barrande is the earliest known pelecypod representatives and comes from Early Cambrian rocks (513-520 Ma) of North America, Greenland, Europe, the Middle East and Asia. Genus Fordilla contains three species, F.germanica, F.sibirica, and the type species F.troyensis.Pojetaia has two species, P.runnegari, the type species, and P. ...e XPL, 5X, Fragments of Pelecypod (Bivalve), Class Pelecypoda. The periostracum of the wall structure is well preserved, and can be seen on the shell in the centre. On the right top corner of the slide a broken fragment of a valve in lateral view is present. f XPL, 15X, Sponge, Phylum Porifera. Fragments of wall structure of sponge, a …Keyword search for 'pelecypod'bonnechere museum fossil hunts - canada day. bonnechere museum fossil hunts - july 22nd, 2023. cavestock concert series - thursday august 24th, 2023 tour de bonnechere - august 27th, 2023 cavestock concert series - thursday august 31st, 2023 paint the waterfall any day you care to! tie dye tuesdays bike from our parking lot anytime you feel like it! the "i climbed the foymount hill" ...The marine nature of the sediments is evident from the recovery of shallow marine benthic foraminifera (Ammobaculites, Haplophragmoides and Ammodiscus), echinoids, brachiopods and pelecypod shells. The carbonaceous units within the Ahoko Formation are interpreted as swamp or salt marsh deposits.Abstract. Specimens of the small bivalved animal Fordilla troyensis Barrande from New York State show that this fossil is the oldest known pelecypod mollusk and not a conchostracan arthropod. This finding extends the range of the class Pelecypoda backward in time from the Early Ordovician (about 495 million years ago) to the Early Cambrian ... A slightly younger bivalve-dominated faunal assemblage, exposed during excavations at Tocal near Paterson, is the first fossiliferous occurrence of Permian age recorded in that area and is ...The Farasan Bank is located in the southern part of the Red Sea, on the eastern shelf, where the Red Sea reaches its maximum width of 360 km (Fig. 1).The Farasan Bank is approximately 3000 km 2 and extends from 16°00′N to 17°15′N with a maximum width of ~120 km. The Farasan Islands are located within this bank at a …Gryphaea, one of the genera known as devil's toenails, is a genus of extinct oysters, marine bivalve mollusks in the family Gryphaeidae . These fossils range from the Triassic period to the middle Paleogene period [citation needed], but are mostly restricted to the Triassic and Jurassic. They are particularly common in many parts of Britain . From this one locality 61 species of echinoderms have been described, including 56 crinoids, 4 cystids, and 1 blastoid. In addition this upper horizon has furnished 7 species of brachiopods, 5 of cephalopods, 5 corals, 1 gastropod, 1 pelecypod, and 1 trilobite.Venericardia, genus of pelecypods (clams) abundant during the Eocene Epoch (the Eocene Epoch began 57.8 million years ago and ended 36.6 million years ago). The shell, composed of two halves (valves), is distinctive in form and generally large. Transverse ribs radiate from the apex of the valves and are broken by a series of concentric growth rings.A manual of the recent and fossil marine Pelecypod mollusks of the Hawaiian islands. Location. AMERICAN SAMOA. Author(s). Dall, W.H.. Publisher. Kraus Reprint.The location of the state of New Mexico. Paleontology in New Mexico refers to paleontological research occurring within or conducted by people from the U.S. state of New Mexico. The fossil record of New Mexico is exceptionally complete and spans almost the entire stratigraphic column. [1] More than 3,300 different kinds of fossil organisms have ...pe·lec·y·pod (pə-lĕs′ə-pŏd′) n. See bivalve. [From New Latin Pelecypoda, class name : Greek pelekus, axe + New Latin -poda, -pod.] American Heritage® Dictionary of ...Jan 5, 2023 · External molds may preserve external ornamentation of the shell, such as growth lines, ribs, and costae (fine ribs). Many bivalve fossils, however, are casts and molds of the internal surface of the shells, so they preserve the shape of the inside surface of the shell, which is usually smooth and lacks growth lines and ornamentation. It is more ... Fossilicious | Shop Quality Minerals & Fossils for Sale OnlineFordilla troyensis Barrande is the earliest known pelecypod representatives and comes from Early Cambrian rocks (513-520 Ma) of North America, Greenland, Europe, the Middle East and Asia. Genus Fordilla contains three species, F.germanica, F.sibirica, and the type species F.troyensis.Pojetaia has two species, P.runnegari, the type species, and P. ...The taxonomic term Bivalvia was first used by Linnaeus in the 10th edition of his Systema Naturae in 1758 to refer to animals having shells composed of two valves. More recently, the class was known as Pelecypoda, meaning "axe-foot" (based on the shape of the foot of the animal when extended). The … See moreExternal molds may preserve external ornamentation of the shell, such as growth lines, ribs, and costae (fine ribs). Many bivalve fossils, however, are casts and molds of the internal surface of the shells, so they preserve the shape of the inside surface of the shell, which is usually smooth and lacks growth lines and ornamentation. It is more ...Bivalves: Phylum Mollusca, Class Bivalvia. Clams, mussels, oysters, and scallops are members to the class Bivalvia (or Pelecypodia). Bivalves have two shells, connected by a flexible ligament, which encase and shield the soft vulnerable parts of the creature. All 15,000 known species of bivalves are aquatic in nature, with close to 80% being ...Bivalves (pelecypods, clams, etc.) Bivalves (also called pelecypods) are clam and clam-like, shelled invertebrate (lacking a backbone) animals. Bivalves are a class of mollusk with two valves, which is where they get their name (“bi” means two in Latin). They are the second-most common seashells in the world today behind their cousins, the ...The HE per locus for genomic SSRs ranged from 0.7011 to 0.7542 (mean HE 0.7276). The highest HE value was detected for RPg15608 (0.8416), and the lowest value was found for RPg16975 (0.6633). At ...Generally, the results of the distribution of metals in the mollusc shells showed that gastropod shells had greater concentrations of Fe, Zn, Ni, and Cd than pelecypod shells (Fig. 4). The reason for this difference is the natural structure of gastropod shells, which are undivided from the interior and have a spiral shape.คำว่า ฟอสซิล (Fossil) มาจากภาษาละติน หมายถึง ถูกขุดขึ้นมา. การเกิดซากดึกดำบรรพ์เป็นกระบวนการทางธรรมชาติที่เกิดขึ้นได้ยากยิ่ง ...The pronounced convexity of the top surface of the massive pile suggests that the sediment-driving flow earned high viscosity prior to deposition. Fairly intact nature of the pelecypod valves corroborates this contention. Chaotic arrangement of the shells, however, suggests turbulence in the flow immediately before turning viscous.Conserving biodiversity in the face of ever-increasing human pressure is hampered by our lack of basic information on species occurrence, distribution, abundance, habitat requirements, and threats. Obtaining this information requires efficient and sensitive methods capable of detecting and quantifying true occurrence and diversity, including …The Pyramid Sea Star, Pharia pyramidata (Grey, 1840) is a member of the Ophidiasteridae Family of Ophidiasterid Sea Stars, that is also known as the Yellow-spotted Sea Star in Mexico as estrella de mar piramide. This is the sole member of the Pharia Genus. Pyramid Sea Stars have a small central disc and long arms that have rounded tips.(Pelecypod, Pterioidea) Jean-Pierre Cuif 1, *, Manfred Burghammer 2, Virginie Chamard 3, Yannicke Dauphin 1, Pierre Godard 3, Gilles Le Moullac 4, Gernot Nehrke 5 and Alberto Perez-Huerta 6 . 1 ...Words that start with PE: pe, pea, pec, ped, pee, peg, peh, pen, pep, perVenericardia, genus of pelecypods (clams) abundant during the Eocene Epoch (the Eocene Epoch began 57.8 million years ago and ended 36.6 million years ago). The shell, composed of two halves (valves), is distinctive in form and generally large. Transverse ribs radiate from the apex of the valves and are broken by a series of concentric growth rings.National Fossil Day. Your best chance of finding a nearby fossil event is on National Fossil Day, which is held in October each year. (In 2018, the event falls on Oct. 17.) The National Park ...• PELECYPOD adj. designating or pertaining to a bivalve mollusc. • PELECYPOD n. a pelecypod mollusc, a bivalve. PERAEOPOD • peraeopod n. (Zoology) One of the thoracic legs of a crustacean. • PERAEOPOD n. each of the eight walking limbs of a crustacean such as a crab or lobster, growing from the thorax, also PEREIOPOD, PEREOPOD.Living slit shells (pleurotomarians) were first discovered alive in 1856. Before this, the group was known only from fossils of Cambrian to Cretaceous age. Living slit shells—of which 15 species are known—are rare and live only in deep water. Gastropod: Bayerotrochus teramachii (PRI 70103) by Digital Atlas of Ancient Life on Sketchfab.Commonly used words are shown in bold.Rare words are dimmed. Click on a word above to view its definition.Feb 8, 2019 · American Thorny Oysters. S. princeps is called "spiny oyster" or "ostra espinosa" in Spanish, and the Quechua (Inca language) word is "mullu" or "muyu". This mollusk is characterized by large, spine-like protuberances on its outer shell, which varies in color from pink to red to orange. The inside of the shell is pearly, but with a thin band of ... Related WordsSynonymsLegend: Switch to new thesaurus Noun 1. class Pelecypoda - oysters; clams; scallops; mussels Bivalvia, class Bivalvia, class Lamellibranchia, Lamellibranchia Mollusca, phylum Mollusca - gastropods; bivalves; cephalopods; chitons bivalve, lamellibranch, pelecypod - marine or freshwater mollusks having a soft body with platelike gills enclosed within two shells hinged ...Harford's Isopod, Cirolana harfordi (Lockington, 1877), is a member of the Cirolanidae Family of Cirolanid Isopods. They have an oval profile and are about 2.5 times longer than they are wide. They are white in color with very fine brown spots that gives the animal a blotch tan or brown overall color. Harford's Isopod reach a maximum length ...Evidence is given to show that when a pelecypod is feeding a sheet of mucus covers the gills, and it is this mucus which strains the food material from the water, the cilia affording mechanical means for its transportation. 4. While the pelecypod is feeding this mucus is constantly being secreted and is carried to the food grooves bordering the ...The Sailfish, Istiophorus platypterus, is a member of the Billfish or Istiophoridae Family, and is known in Mexico as pez vela. They are one of the smallest members of the family. This is the only species in the genus Istiophorus and it is found in Mexican waters of both the Atlantic and the Pacific, being one of the few fish found in Mexican ...Living slit shells (pleurotomarians) were first discovered alive in 1856. Before this, the group was known only from fossils of Cambrian to Cretaceous age. Living slit shells—of which 15 species are known—are rare and live only in deep water. Gastropod: Bayerotrochus teramachii (PRI 70103) by Digital Atlas of Ancient Life on Sketchfab.Length: 12.2 cm (4.8 inches). Catch, photograph and identification courtesy of Ben Cantrell, San Diego, California. The Woolly Sculpin, Clinocottus analis, is a member of the Sculpin or Cottidae Family, that is also known under the incorrectly spelled Wooly Sculpin and in Mexico as charrasco lanudo.National Fossil Day. Your best chance of finding a nearby fossil event is on National Fossil Day, which is held in October each year. (In 2018, the event falls on Oct. 17.) The National Park ...PALEOZOIC PELECYPOD By DAVID NICOL Stanford University, California While the writer was collecting data on the validity of reports of Paleozoic Ostreidae, he found that the question of the time of origin of shell attachment in pleurothetic pelecypods was impor- tant. Especially for this latter problem, it was necessary to ...pelecypod. Advertising. Syllables. Scrabble Words with friends Wordfeud Apalabrados Letterpress Wordle Wordscapes Words of Wonders Spelling Bee Crossword Definitions Thesaurus Proverbs Abbreviations Verb conjugator Sentences Quotes Syllables Parts of speech Numbers to words Phonetic Spelling Rhymes Text to speech.The following points highlight the six main classes of phylum mollusca. The classes are: 1. Monoplacophora 2. Amphineura 3. Gastropoda 4. Scaphopoda 5. Pelecypoda or Bivalvia or Lamellibranchiata 6. Cephalopoda. Class # 1. Monoplacophora: 1. The body is bilaterally symmetrical and covered by a mantle. 2. The single dorsal shell is thin and sub circular. 3. The metamerism is apparent and not ...The pelecypod genera Slava and Rhombopteria are reported for the first time from Canada, where they occur in a limestone concretion within the Cape Phillips Formation, Cornwallis Island, Arctic Archipelago. These genera are characteristic of Silurian rocks in Bohemia, Czechoslovakia. Graptolites from the same concretion indicate the Monograptus ludensis Zone (uppermost Wenlockian); this age is subForaminifera—witness of the evolving Earth. Pratul Kumar Saraswati, in Foraminiferal Micropaleontology for Understanding Earth's History, 2021. Abstract. Foraminifera witnessed the evolving Earth and recorded significant shifts in climate, sea levels, and catastrophes in the Phanerozoic Eon. This chapter begins with an overview of how oceanic processes control the distribution of modern ...Fish caught from coastal waters off Point Palmilla, Baja California Sur, September 2013. Length: 48 cm (19 inches). The Goldspotted Sand Bass, Paralabrax auroguttatus, is a member of the Sea Bass or Serranidae Family, and is known in Mexico as cabrilla extranjera. Globally, there are nine species in the genus Paralabrax, of which five are …Hinge teeth are part of the anatomical structure of the inner surface of a bivalve shell, i.e. the shell of a bivalve mollusk. Bivalves by definition have two valves, which are joined together by a strong and flexible ligament situated on the hinge line at the dorsal edge of the shell. In life, the shell needs to be able to open slightly to ...Bivalves: Phylum Mollusca, Class Bivalvia. Clams, mussels, oysters, and scallops are members to the class Bivalvia (or Pelecypodia). Bivalves have two shells, connected by a flexible ligament, which encase and shield the soft vulnerable parts of the creature. All 15,000 known species of bivalves are aquatic in nature, with close to 80% being ...Two new species of the genus Crassatella, C. imitatoris sp. nov. and C. pseudolamellosa sp. nov., from Upper Eocene detrital sands of the Rybal'sky quarry of Dnepropetrovsk are described. The species Crassatella oblongula Klushnikov, 1958 is redescribed as a variety.In pelecypod nacre, nacre laminae on the growth surface overlap into a stairs-like pattern, and new crystals deposit at the stairs-like front. In the vertical sections, pelecypod nacre looks like an arrangement of bricks in a wall. Pelecypod nacre is known as "sheet nacre" (Rousseau et al. 2005a, b). Bivalve nacre is representative of sheet ...This finding extends the range of the class Pelecypoda backward in time from the Early Ordovician (about 495 million years ago) to the Early Cambrian (about 540 to 570 million years ago). The morphology of Fordilla troyensis suggests that it lived infaunally and that it was ancestral to the pelecypod subclasses Heteroconchia and Isofilibranchia.Lumachelle - iridescent fossil pelecypod shells that occur within a dark gray or brownish marble that occurs in the vicinity of Bleiberg, Kärnten, Austria. Madammolite - iridescent ammonite from Madagascar that has been fashoined into cabochons and various other shapes have been marketed under this name (Laurs, 2011).revised by Lamy (1920), have been known in collections since the time of. Linnaeus. Because of their great variability in shape, colour and sculpture,.Oct 20, 2023 · Heterodonta is a subclass of bivalves that burrow, including clams. Pteriomorphia is a subclass of bivalves that attach to rocks, including oysters (order Ostreoida, family Ostreidae), scallops (order Ostreoida, family Pectinidae) and mussels (order Mytiloida). There are a few key differences between these four types of bivalve mollusks ... The skeletal system in the human body helps in its locomotion. Different types of bones and muscles take part in the locomotory action. In the case of birds and animals, their body structure is different from that of humans. Also, the mode of locomotion varies from one animal to another. Hence, each organism has its own structural makeup which ...The pronounced convexity of the top surface of the massive pile suggests that the sediment-driving flow earned high viscosity prior to deposition. Fairly intact nature of the pelecypod valves corroborates this contention. Chaotic arrangement of the shells, however, suggests turbulence in the flow immediately before turning viscous.George Poinar Jr. and Roberta Poinar explore how dinosaurs may have competed with insects for plants, how insects provided food for dinosaurs, and, most significantly, how dinosaurs very likely were meals for blood-feeding and parasitic arthropods. In fact, they propose that diseases spread by arthropods contributed to the …2. Now, look for a card that has either a "T" or "C" written on it. Since this card has a common letter with the first card, it must go on top of the "TC" card. The fossils represented by the letters on this card are "younger" than the "T" or "C" fossils on the "TC" card which represents fossils in the oldest rock layer.Tortello, M. Franco 2014: A Systematic Revision of the Late Furongian Trilobites from Cerro Pelado, Mendoza, Argentina Ameghiniana 51 (4): 295-310. Heredia, S. 1999: Upper Cambrian paraconodonts from Cerro Pelado, Precordillera, Mendoza Province, Argentina Ameghiniana 36 (3): 345-358. Rusconi, C. 1954: Trilobitas Cambricos de la quebrada Oblcua ...6.2.1 Paleozoic Source Rocks 6.2.1.1 Qusaiba Formation. The Lower Silurian organic-rich mudstone of Qusaiba Formation of the Qalibah Group is accepted to be the source rock for most Permian reservoirs in the Arabian Peninsula (Mahmoud et al., 1992; Abu-Ali et al., 1999; Parmijit et al., 2010), and it is also considered as one of the effective …6.2.1 Paleozoic Source Rocks 6.2.1.1 Qusaiba Formation. The Lower Silurian organic-rich mudstone of Qusaiba Formation of the Qalibah Group is accepted to be the source rock for most Permian reservoirs in the Arabian Peninsula (Mahmoud et al., 1992; Abu-Ali et al., 1999; Parmijit et al., 2010), and it is also considered as one of the effective …Hello, In this video, Rubiyth Sharmin Maria described the Hinge line structures and Dentition of Pelecypoda. In our today's Invertebrate paleontology PowerPo...Pelecypods. Means "two shells". Bivalve. Members of this class: oysters, mussels, clams, scallops, and shipworms. Shipworms. burrow in wood, causing damage to unprotected wooden hulls and piers. Most are sessile except when. they search for food.Pedogenic limestone Pelecypod floatstone/ rudstone Quartz sandstone Skeletal sandstone S floatstone/rudstone andy pelecypod Rock-Fabric Facies Miscellaneous HFC3a HFC2 HFC1? HFC5 HFC4 HFC3b High-Frequency Cycles Leaky low permeability zone Low permeability peat, muck, and marl Lateral conduit Diffuse flow zone flow zonePelecypod shell originated from Kolleru lake of Andhra Pradesh is used in the present work. It contains Mn(II) and Fe(III) in traces. The EPR spectrum of the compound is due to Mn(II) which is in three independent sites. The three g values are evaluated with slight differences. The hyperfine component varies from 9.33 to 9.49 mT. The zero field splitting parameter is also ranges from 43.8(1 ...अंग्रेज़ी शब्दकोश में उदाहरणों के साथ pelecypod का अर्थ। pelecypod के पर्यायवाची और 25 भाषाओं के लिए pelecypod का अनुवाद।Offered here is a killer sea floor plate from the Waldron Shale Formation from Blue Springs Quarry (filled with water) in Waldron, Indiana, Silurian in age. The main piece is the rare, ventral pelecypod that measures 2 1/8" wide and sits in a matrix piece that measures about 5" x 3 1/2". The pelecypod was meticulously prepared under a ...Pelecypoda are also called asA.BivalviaB.LamellibranchiaC. Both A BD.None of the above. Ans: Hint:Numerous freshwater and marine molluscs, including clams, ...Tellinopsis subemarginata? pelecypod fossil from the Moscow formation The fossil below is defying my attempts to identify it. It has a rectangular shaped shell with a rounded anterior and posterior. The umbo is near the middle but off center and angled to the anterior end. There are very fine radiating striae (ribs) and concentric growth lines ...Edge of a pelecypod shell where the other<br /> half of shell, or valve, was attached.<br /> hinge line<br /> Mark on the interior of pelecypod shell<br /> where strong muscle was attached. The<br /> muscles hold the shell tightly closed.<br /> muscle scar<br /> Raised ridges on the outside of the shell.<br /> Winding away from the center.<br />trawled shelves site. Key words: diversity, pelecypods, gastropods, Chaungtha Coastal Area. Introduction. The phylum Mollusca is divided ...Lumachelle - iridescent fossil pelecypod shells that occur within a dark gray or brownish marble that occurs in the vicinity of Bleiberg, Kärnten, Austria. Madammolite - iridescent ammonite from Madagascar that has been fashoined into cabochons and various other shapes have been marketed under this name (Laurs, 2011).Don L. Frizzell was born on 19 October 1906 in Bellingham, Washington. [2] He attended grade school in White Bird, Idaho. [3] In 1926, Frizzell entered the University of Washington in Seattle where he received master's degree in zoology under the direction of Professor Kincaid. [3] During 1930–1931, he published three papers in Nautilus and ...Gastropod, any member of more than 65,000 animal spec, • PELECYPOD adj. designating or pertaining to a bivalve mollusc. • PELECYPOD n. a pele, Abigail E. Cahill, Alia Rehana Juman, Aaron Pellman-Isaacs, and William T. Bruno Physical and Chemical Int, Invertebratesany mollusk of the class Pelecypoda (Lamellibranchiata), characterized by a bivalve shell enclosing the hea, The Pacific Hake is a coastal and offshore pelagic schooling species, Bivalve: Mercenaria mercenaria (PRI 76728) by Digital Atlas of Ancient Life on Sketchfab. , (Pelecypod, Pterioidea) Jean-Pierre Cuif 1,*, Manfred Burghammer 2, Virginie Chamard 3, Yannicke Dauphin 1, Pi, The pelecypod beds are invariably interbedded with , Bivalves are highly specialized not only in their s, Pelecypod. Large, imperfect specimen, showing convex form and, In muscle: Mollusks. …highly muscular organ called the foot, through w, 7 Pelecypod synonyms. What are another words for Pelecypod? , The Spotted Cabrilla is found both in rocky reefs and , McChesney, J. H., 1860, Descriptions of new species of fossi, The Ribbed Ark, Arca gradata, a representative Bivalve or , proving that it is a pelecypod are in-ternal molds t, Pelecypod (freshwater bivalves) and gastropod (freshwater, Station 2, Pelecypod or burrowing bivalves, Veneroida (M.