Life habit,feeding mechanism and population structure of the Cretaceous brachiopod genus Aemula

Comparison with close Recent relatives, studies of functional morphology and the discovery of specimens preserved in life position indicate with a high degree of certainty the mode of life of the Cretaceous brachiopod genus Aemula. This genus is an important member of the brachiopod communities of the north European Maastrichtian.In resting position Aemula lived with its dorsal valve pressed against the substrate. When feeding the shell was somewhat elevated anteriorly and the two valves gaped at an angle of about 45°. Preserved calcitic mesodermal spicular skeletons show that the adult lophophore was a schizolophe. During the younger stages only one inhalant feeding current flowed into the bell-shaped trocholophe and early schizolophe, whereas the exhalant current flowed out in all directions between the filaments.In the later stages when the schizolophe was fully developed the current system was divided into two lateral inhalant and one median exhalant current. The species Aemula inusitata has been investigated with regard to size frequency and survivorship revealing an initially very high, but slightly decreasing mortality rate corresponding to the dangerous life on small substrates close to the sediment—water interface of the muddy-chalk sea bottom. The species of Aemula never dominate the brachiopod assemblages of the Maastrichtian chalk but is found in almost all samples in small but rather constant numbers.     

Discovery of ventrally directed spiralia in a Permian spiriferellid brachiopod and implications for its feeding system

Spiralia are lophophore‐supporting, coiled internal structures developed in some extinct brachiopods. In spite of considerable variations in their orientation, the spiralia of most spiriferide and spiriferinide taxa are known to be laterally directed. Recent studies have shown that these brachiopods consistently have a median inhalant and lateral exhalant feeding system. Here, we report a Permian spiriferellid brachiopod fossil (Spiriferella protodraschei) bearing ventrally directed spiralia in its interior. Using the serial sections of the specimen, we have reconstructed the detailed morphology and orientation of the spiralia. Each spiralium in the specimen does not show the apically tapering pattern supposedly universal in all the known types of spiralia: instead it maintains a similar diameter even at its last whorl. The spiralia appear to have directly developed from strong and anteriorly extended crura, consisting of ten whorls in one side and 13 whorls in the other side. As the morphology and orientation of spiralia are immediately associated with the arrangement of spirolophous lophophore within the mantle cavity, the extraordinary orientation and form of the spiralia indicate that this brachiopod likely had developed a considerably modified feeding pattern with respect to most other spirolophous brachiopods. It is postulated that the inhalant/exhalant current circulation of the species (and its descendants) would be considerably different from that of other spiriferide taxa. In particular, the combination of the vertically oriented life posture (free‐lying with thickened ventral apex bottom) and ventrally directed spiralia resembles both fossil atrypide and modern rhynchonellide brachiopods in the orientation of spirolophe, suggesting that some spiriferellid brachiopods may have developed a lateral inhalant/median exhalant feeding current system. A few spiriferide and spiriferinide brachiopod taxa with a weakly transverse but strongly convex ventral valve are noted to exhibit similar modifications in their spiralia, possibly due to the spatial limitation of their mantle cavities.     

The biology and functional morphology of Pteria brevialata (Bivalvia: Pterioidea), epizoic on gorgonians in Hong Kong

Pteria brevialata characteristically attaches to Hicksonella princeps (Cnidaria: Gorgonoidea) at depths > 10 m in Hong Kong and the South China Sea. Attachment is by a stout byssus to the basal regions of the gorgonian colonies. The shell appears typical of the Pteriidae, but closer inspection shows that the antero-ventral margin, in particular, moulds itself to the form of the cylindrical gorgonian, which also changes its growth form, so that securer attachment is achieved. The margin of the right valve is not nacred so that the flexible outer prismatic layer adpresses firmly against the more extensively nacred left valve when they close; mantle and ctenidia also being withdrawn deeply. This is probably an anti-predation device. There are no mantle fusions, even between posterior inhalant and exhalant streams. The mantle margin is, however, complexly tentaculate. Pteria brevialata is monomyarian with reduced anterior byssal retractor muscles. The anterior face of the shell is thus greatly reduced whereas the posterior is inflated and postero-dorsally 'winged'.
Other features of the anatomy are described, including the ctenidial eyespot and simple photoreceptors in the inner component of the duplicated outer mantle folds, under the periostracum. Similar structures in other pterioideans and arcoideans suggest a close relationship between their respective orders.
It is concluded that gorgonian-associated pterioids can be derived from an epibyssate, crevice-dwelling ancestor, exploiting, as solitary individuals, the currents and clean oceanic waters above the substratum. This has three important advantages: (a) removal from surface-roving predators (the gorgonian providing additional protection); (b) exploitation of a niche hitherto unoccupied by bivalves and (c) removal of the animal from the sea-bed and exclusive exploitation of potential food held in suspension. Current stresses to attachment are avoided by modifications to the shell.     

The biology and functional morphology of Arca noae (Bivalvia: Arcidae) from the Adriatic Sea, Croatia, with a discussion on the evolution of the bivalve mantle margin

In the Croatian Adriatic, Arca noae occurs from the low intertidal to a depth of 60 m; it can live for > 15 years and is either solitary or forms byssally attached clumps with Modiolus barbatus. The shell is anteriorly foreshortened and posteriorly elongate. The major inhalant flow is from the posterior although a remnant anterior stream is retained. There are no anterior but huge posterior byssal retractor muscles and both anterior and posterior pedal retractors. The ctenidia are of Type B(1a) and the ctenidial–labial palp junction is Category 3. The ctenidia collect, filter and undertake the primary sorting of potential food in the inhalant water. The labial palps are small with simple re‐sorting tracks on the ridges of their inner surfaces. The ciliary currents of the mantle cavity appear largely concerned with the rejection of particulate material. The mantle margin comprises an outer and an (either) inner or middle fold. The outer fold is divided into outer and inner components that secrete the shell and are photo‐sensory, respectively. The latter bears a large number of pallial eyes, especially posteriorly. The inner/middle mantle fold of A. noae, possibly representative of simpler, more primitive conditions, may have differentiated into distinct folds in other recent representatives of the Bivalvia.     

Valve orientation and functional morphology of the foramen of some siphonotretacean and acrotretacean brachiopods

It has recently been suggested that the foramen of siphonotretacean and acrotretacean brachiopods functioned as an exhalant siphon and that it was a feature of the dorsal valve. In representatives of these superfamilies the pedicle was considered to have emerged from between the valves. Re-examination of the evidence on which these arguments were based suggests that some of it is capable of more than one interpretation. The remainder, together with consideration of the mantle canal patterns, cemented mode of attachment, and comparative morphology of some discinaceans and siphonotretaceans, strongly supports the traditional view that the foramen of these forms was located in the ventral valve and that it served as a pedicle opening.     

Respiratory significance of the external morphology of adults and fifth instar nymphs of Notonecta undulata Say (Aquatic Heteroptera; Notonectidae)

The bodies of adult and fifth instar Notonecta possess external air stores which are periodically renewed at the surface of the water. Both nymphs and adults have large ventral air stores on the thorax and abdomen and obtain atmospheric air at the posterior end of the latter; the adult also has dorsal subalar and supra-alar air stores on both these regions. Ten pairs of spiracles open onto the air stores. Although the seven small, ventrally placed abdominal spiracles are probably both exhalant and inhalant in nymphs and adults, the three large anterior spiracles (mesothoracic, metathoracic, and first abdominal), which play a more important respiratory role, appear to function differently in mature and immature Notonecta. In the nymph they are probably both inhalant and exhalant, and communicate broadly with each other and with the ventral air stores. In the adult, however, they open onto separate, air-filled chambers, each of which communicates differently with various parts of the air stores. Although all three probably function in exhalation, only the first abdominal spiracle, whose spiracular chamber is widely continuous with the dorsal and ventral air stores, appears to be well suited for inhalation. Several morphological features, most notably the development of long prothoracic lobes, separate spiracular chambers, and long, movable forewings, allow the adult a greater variety of respiratory modes than are available to the nymph. Some of the respiratory advantages of the adult are: (1) a larger amount of stored air; (2) a longer subalar air store, which can serve as an alternate pathway between the air stores and the atmosphere; (3) a greater capacity to utilize dissolved as well as atmospheric oxygen; (4) greater separation and functional specialization of the three anterior spiracles, thus allowing more separation of exhaled air from oxygen-rich air on the external surface of the thorax; (5) the probable ability to regulate the continuity between various parts of the air stores, thus utilizing alternate pathways of air circulation and/or changing the functions of the three anterior spiracles; and (6) better protection of the latter against the entry of water during prolonged submergence.     

The functional morphology of the abyssal Limopsis cristata (Arcoida: Limopsidae) with a discussion on the evolution of the more advanced bivalve foot

The bivalve Limopsis cristata pursues a semi‐endobenthic life in abyssal soft sediments. It attaches to particles by up to three byssal threads and filter feeds by inhaling water from posterior and anterior directions. Because of partial burial, however, only the latter is functionally significant. Complex ciliary currents in the mantle cavity concerned with the rejection of unwanted particles keep most material out of the simplified intestine. It is generally considered that the ligament is the constraining force in arcoid evolution. This may be true in part, but the lack of pallial fusions and the retention of anterior and posterior inhalant flows are more powerful limits to radiation in the Arcoida. In the deep sea, the Limopsidae has radiated into many micro‐niches through micro‐morphological adaptations. Loss of the arcoid ‘heel’ has resulted in the union of the separate rejectory currents of the visceral mass and foot, creating a single discharge point in more advanced bivalves. This greatly simplifies the rejectory roles of the visceral mass and foot and is thus of functional and selective advantage.     

Signaling via water currents in behavioral interactions of snapping shrimp (Alpheus heterochaelis)

The snappping shrimp Alpheus heterochaelis produces a variety of different water currents during intraspecific encounters and interspecific interactions with small sympatric crabs (Eurypanopeus depressus). We studied the mechanisms of current production in tethered shrimp and the use of the different currents in freely behaving animals. The beating of the pleopods results in strong posteriorly directed currents. Although they reach rather far, these currents show no distinctions when directed toward different opponents. Gill currents are produced by movements of the scaphognathites (the exopodites of the second maxillae) and can then be deflected laterally by movements of the exopodites of the first and second maxillipeds. These frequent but slow lateral gill currents are most probably used to enhance chemical odor perception. The fast and focused, anteriorly directed gill currents, however, represent a powerful tool in intraspecific signaling, because they reach the chemo- and mechanosensory antennules of the opponent more often than any other currents and also because they are produced soon after previous contacts between the animals. They may carry chemical information about the social status of their producers since dominant shrimp release more anterior gill currents and more water jets than subordinate animals in intrasexual interactions.     

Life habits and functional morphology of the sediment infaunal spongesOceanapia oleracea andOceanapia peltata (Porifera,Haplosclerida)

Summary In the Santa Marta area of the northern coast of Colombia two species of sponges have been found living within the sediment. The only connection these sponges have with the open water consists of a number of protruding, tubule-like siphons. Through field observations and aquarium experiments, the life habits and the function of the water current system ofOceanapia oleracea andO. peltata have been studied. As an adaptation to life embedded in sediment, both species possess inhalant siphons which draw water from above the sediment surface and duct it to the central body. The inhalant system shows a most unusual separation and concentration of inhalant pores at the tips of the inhalant ducts. The exhalant water leaves the sponge through separate ducts at the opposite side of the central body. Based on the observations onOceanapia, the water flow model forDisyringa proposed by Fry and Fry (1979) is reconsidered.     

Giant scallop feeding and growth responses to flow

The relationship between ambient seawater flow velocity and growth of the giant scallop Placopecten magellanicus Gmelin is shown to be a reverse ramp function with growth inhibition at flow velocities of > 10–20 cm · s⁻¹. The mechanism of inhibition involves a reduction in ration as velocities around the scallop increase. In ambient flows which are sufficient to cause overloading of the scallop gill, the feeding/filtration rate is reduced by an unknown mechanism, possibly involving the mantle edge closing or a gill bypass mechanism operating. In ambient flows where the pressure at the exhalant opening exceeds the inhalant plus the pressure head created by the gill, as when the scallop is placed dorsal edge to the flow, the tendency for flow reversal is resisted by a similar mechanism involving a reduction in feeding/filtration rate.     

Fate of the anterior neural ridge and the morphogenesis of the xenopus forebrain

The fate of the anterior neural ridge was studied by following the relative movements of simultaneous spot applications of DiI and DiO from stage 15 through stage 45. These dye movements were mapped onto the neuroepithelium of the developing brain whose shape was gleaned from whole-mount in situs to neural cell adhesion molecule and dissections of the developing nervous system. The result is a model of the cell movements that drive the morphogenesis of the forebrain. The midanterior ridge moves inside and drops down along the most anterior wall of the neural tube. It then pushes forward a bit, rotates ventrally during forebrain flexing, and gives rise to the chiasmatic ridge and anterior hypothalamus. The midanterior plate drops, forming the floor of the forebrain ventricle, and, keeping its place behind the ridge, it gives rise to the posterior hypothalamus or infundibulum. The midlateral anterior ridge slides into the lateral anterior wall of the neural tube and stretches laterally into the optic stalk and retina, and then rotates into a ventral position. The lateral anterior ridge converges to the most anterior part of the dorsal midline during neural tube closure, then rotates anteriorly, and gives rise to telencephalic structures. Whole-mount bromodeoxyuridine labeling at these stages showed that cell division is widespread and relatively uniform throughout the brain during the late neurula and early tailbud stages, but that during late tailbud stages cell division becomes restricted to specific proliferative zones. We conclude that the early morphogenesis of the brain is carried out largely by choreographed cell movements and that later morphogenesis depends on spatially restricted patterns of cell division. © 1995 John Wiley & Sons, Inc.     

The inference of extrazooidal feeding currents in fossil bryozoan colonies

Taylor, Paul D. 1979 01 15: The inference of extrazooidal feeding currents in fossil bryozoan colonies. Lethaia , Vol. 12, pp. 47–56. Oslo. ISSN 0024–1164.
Previous studies on live bryozoan colonies have shown that the feeding autozooids in a colony may cooperate in differing ways to produce an extrazooidal watercurrent system organised on a colony-wide or subcolony-wide basis. The presence of an extrazooidal current system may be inferred in fossil stenolaemate bryozoans which exhibit either a differential spacing of open autozooecial apertures or a systematic variation across the marial surface in the orientation of automoecial distal portions. By inference, aggregations of autozooecial apertures represented loci of inhalant extrazooidal flow whereas zoarial protuberances (e.g. monticules) with outwardly leaning autozooecia acted as loci of exhalant extrazooidal flow. Bryozoans having automoecia opening obliquely into gaps or fenestrules in their zoaria probably drew a unidirectional extrazooidal current of water through the fenestrules. Extrazooidal water currents may function to accelerate colony clearance rate, decrease the chances of recycling filtered water, aid spermatoman and larval dispersal, and clear sediment from the colony surface.     

Morphological and ecological adaptation of Basterotia bivalves (Galeommatoidea: Sportellidae) to symbiotic association with burrowing echiuran worms

The burrows created by benthos in tidal flats provide various habitats to other organisms. Echiuran burrows are unique among these in being persistently disturbed by the host's undulating activity, but little is known on how symbionts adapt to such a unique habitat. We report here the morphological and ecological adaptation by two bivalve species of Basterotia (Sportellidae), including one new species, which are commensals with burrowing echiuran worms. The burrows of Ikedosoma gogoshimense were inhabited by Basterotia gouldi at intertidal gravelly mud flats in the central Seto Inland Sea, whereas those of Ochetostoma erythrogrammon were inhabited by Basterotia carinata n. sp. at an intertidal gravelly coral-sand flat at Amami-Ohshima Island. Both bivalve species were found embedded in the burrow wall with their posterior inhalant and exhalant apertures gaping to the burrow lumen, suggesting that they utilize the water currents created by host echiurans. The posteriorly robust, laterally inflated shell with developed carina is considered an adaptation to symbiotic life, as it is exposed to pressure caused by the host's persistent undulating activity. Females of Basterotia bivalves were larger than males, suggesting size-dependent sex change, and possessed brooded veligers in the ctenidium. Our findings suggest that species-specific intimate association with echiurans may be widespread among the Sportellidae bivalves, whose biology remains poorly understood.     

A SECOND GONDWANAN DIPLODOCID DINOSAUR FROM THE UPPER JURASSIC TENDAGURU BEDS OF TANZANIA, EAST AFRICA

Abstract:  A new genus and species of diplodocid sauropod (Sauropoda, Diplodocoidea), Australodocus bohetii , is described. The type material from the Upper Jurassic (Tithonian) Tendaguru Beds of Tanzania, East Africa, consists of two successive mid-cervical vertebrae. These vertebrae do not show the extreme elongation of the cervical vertebrae that is diagnostic for Tornieria , and, apart from proportional differences, exhibit four autapomorphic characters not seen in other diplodocids: (1) pleurocoel weakly developed; (2) ridge posterolateral to the anterior condyle strongly posteroventrally orientated; (3) triangular pneumatic cavity ventral to the prezygapophysis, enclosed by the lateral ramus of the centroprezygapophyseal lamina and an anteriorly extended prezygodiapophyseal lamina; and (4) prominent prezygapophyseal process pointed, laterally keeled and surpassing the prezygapophysis anteriorly. Australodocus bohetii is the second diplodocid known from Tendaguru, and thereby the second diplodocid known from Gondwana. This impedes the customary reference of isolated East African diplodocid material to Tornieria , which can now only be assigned to Diplodocidae indet. The find supports previously proposed vicariance models of diplodocid palaeobiogeography.     

Structure of the brachiopod lophophore

Data on the development, structure, and functional morphology of the brachiopod lophophore are analyzed. The common origin of the tentacle apparatus in Lophophorata from the postoral ciliary band of the larva is shown. The brachiopod lophophore is based on the brachial axis consisting of the brachial fold running along the row of tentacles. The brachial axis may be attached to the brachial (dorsal) mantle lobe (trocholophe, schizolophe, and ptycholophe lophophores) or extend freely into the mantle cavity to form coiling brachia (spirolophe, zygolophe, and plectolophe lophophores). The circulation of water flows through the mantle cavity in the brachiopods with attached and free lophophores is described. A new hypothesis on the sorting of particles suspended in water during filtration is proposed.     

Cytoarchitectonic pattern of the hypothalamus in the crocodile,Gavialis gangeticus

Summary The hypothalamus of the crocodile, Gavialis gangeticus, was investigated to reveal the organization of various nuclear complexes and to suggest homologies. The hypothalamic nuclei of G. gangeticus are composed of magnocellular and parvocellular neuronal entities. In the magnocellular system the nucleus supraopticus is well developed, whereas the nucleus paraventricularis and nucleus retrochiasmaticus are represented by scattered somata. Application of cytoarchitectonic criteria permits the delineation of 24 distinct parvocellular nuclear complexes extending rostrocaudally from the anterior commissure to the level indicated by the median eminence and nucleus mamillaris; some are further divisible into subgroups. The nucleus of the preoptic recess appears to be a unique property of the crocodilian hypothalamus. The nucleus suprachiasmaticus possesses a wing-like ventrolateral expansion that protrudes along the lateral aspect of the optic nerve. The tuberal region displays an elaborate pattern of nuclei segregated by regional specializations of the neuropil. The nucleus hypothalamicus posterior occupies the periventricular zone, flanked laterally by the nucleus hypothalamicus dorsomedialis and nucleus arcuatus. Further laterally, extended subdivisions of the nucleus hypothalamicus lateralis contain neurons rich in Nissl substance; the specializations shown by these subdivisions, in comparison to the lateral cell groups in lizards and snakes, are suggestive of enhanced integrative functions. The conspicuous paraventricular organ is encircled by dorsal and ventral divisions of the nucleus of the paraventricular organ. The neurons of the nucleus subfornicalis and nucleus hypothalamicus medialis are few in number, but large in size. The general organization of the hypothalamus of G. gangeticus reveals a mosaic-like pattern with the constituent groups appearing as clusters of small and large neurons, arranged medially and laterally in a definitive manner and accompanied by extensive zones of neuropil in the subependymal and lateral zones of the hypothalamus. The median eminence is divisible into an anterior and a posterior region. The nuclear pattern in the crocodilian hypothalamus reveals a higher state of morphologic organization compared to the situation in lizards or snakes, and thus reflects an evolutionary trend in the avian direction.     

A soft-bodied lophophorate from the Silurian of England

Soft-bodied taxa comprise an important component of the extant lophophorate fauna, but convincing fossils of soft-bodied lophophorates are extremely rare. A small fossil lophophorate, attached to a brachiopod dorsal valve, is described from the Silurian (Wenlock Series) Herefordshire Lagerstätte of England. This unmineralized organism was bilaterally symmetrical and comprised a subconical body attached basally to the host and partially enclosed by a broad ‘hood’; the body bore a small, coiled lophophore. Where the hood attached laterally, there is a series of transverse ridges and furrows. The affinities of this organism probably lie with Brachiopoda; the hood is interpreted as the homologue of a dorsal valve/mantle lobe, and the attachment as the homologue of the ventral valve and/or pedicle. The ridges are arranged in a manner that suggests constructional serial repetition, indicating that they are unlikely to represent mantle canals. Extant brachiopods are not serially structured, but morphological and molecular evidence suggests that their ancestors were. The new organism may belong to the brachiopod stem group, and might also represent a significant element of the Palaeozoic lophophorate fauna.     

INÄQUIVALVER SCHALENBAU BEI CRANIA ANOMALA

As a result of attachment over its entire surface, the ventral valve of the brachiopod Crania anomala (Müiller) differs from the dorsal valve not only in growth form, time sequence of calcification, and distribution of endopuncta, but also (withoutap-parent functional reason) in ultrastructure. The secondary layer of the dorsal valve grows together from flat crystals (up to 5μ. diameter) showing screw-like dislocations. The same layer of the ventral valve is formed later and has an irregular structure. Spiral crystals are not secreted in the ventral valve until the adult growth-stage is attained. The periostracum and primary layer are developed in both valves in a normal fashion. Fossil representatives, in which the ventral valve is partly or completely free, show the same ultrastructure in both valves.
Infolge ganzflächiger Anheftung weicht die Ventralklappe von Crania anomala (Müller) nicht nur in Wuchsform, zeitlichem Ablauf der Kalzifikation und Verteilung der Endopuncta von der Dorsalklappe ab, sondern ohne erkennbare funktionelle Gründe auch in der Ultrastruktur. Während die Sekundärschicht in der Dorsalklappe aus spezifischen, bis 5μ. Großen Kristallen mit Schrauben-versetzungen zusammenwächst, wird sie in der Ventralklappe verzögert und mit regelloser Struktur angelegt. Erst in adulten Wachstumsstadien können auch in der Ventralklappe spiralige Kristalle abgeschieden werden. Periostrakum und Primärschicht sind bei C. anomala normal entwickelt. Fossile Anpassungstypen der Craniacea, deren Ventralklappen nur punktförmig oder überhaupt nicht zementiert sind, zeigen in beiden Klappen dieselbe Ultrastruktur.     

A NEW EARLY CARBONIFEROUS MICRO-PRODUCTID BRACHIOPOD FROM SOUTH CHINA

Abstract:  We describe Muhuarina haeretica gen. et sp. nov. from a recently discovered silicified brachiopod fauna from the Lower Carboniferous of South China. This new microproductid appears to be the oldest representative of the highly differentiated, mainly Permian, aulostegoid family Cooperinidae. The internal structure of the dorsal valve of M. haeretica is dominated by strongly developed, pronounced subperipheral ridges, which suggest support for a simple schizolophe type of lophophore. Brachial ridges, as in other productides, most probably represent an attachment area of the lophophore to the dorsal epithelium. An attempt to homologize subperipheral and brachial ridges among Cooperinidae is presented.     

Functional disposition of the lophophore in living Brachiopoda

Emig, C. C. 1992 07 15: Functional disposition of the lophophore in living Brachiopoda.
The shape and disposition of adult brachiopod lophophores relate to in- and excurrent apertures. to the internal water irrigation system, to shell orientation at substratum and to near-bottom currents. The arrangement of the mantle canals and gonads of different lophophores are induccd by water circulation. The trocholophe (2% of living species) is considered as a plesiomorphic character which represents the basic plan of the lophophore, shared by all Lophophorata. Three different types of schizolophe (10%) are represented in terebratuloids, thecidioids and discinids. The spirolophe (19%), characteristic of rhynchonellides and most inarticulate brachiopods, except the schizolophe Pelagodiscus , has evolved divergently into specific arrangements of the mantle canals and gonads. The zygo-plectolophe (67%) is characteristic of most Terebratulida. The ptycholophe (2%) probably evolved independently in Megathlris and the thecidioids. The mesolophe, known in the fossil chonetdceans, is considered to be a primitive zygo-plectolophe. The median brachiopod sulcus increases the efficiency of the excurrent system and is considered as an evolved character but a homoplasy within the brachiopods. The characteristics of Recent lophophore types have to be taken into account when reconstructing the lophophore in fossil forms. Brachiopoda, Lophophorata, lophophore, water system, orientation, evolution .