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1.
Abstract

Peculiar meniscate burrows with three sediment cords occur in early to middle Miocene tidal-flat deposits of southwestern Japan. Two of the cords are situated at the bottom and the other is at its center. Detailed observations of the burrow structures and comparative neoichnological studies of modern spatangoid burrows in a tidal flat revealed that the former two were true drainage tubes and the latter was fecal in origin. The trace fossil was thus assigned to the ichnogenus Scolicia. Based on these findings, a new ichnospecies Scolicia shirahamensis isp. nov. has been described here. The central sediment cord is seemingly identical to the drainage tube of the ichnogenus Bichordites, another ichnogenus that has been commonly ascribed to a fossil spatangoid burrow, similar to Scolicia. Careless ichnogeneric identification of a spatangoid burrow, based only on the central sediment cord, therefore, may produce an incorrect identification.  相似文献   

2.
Sören Jensen 《Ichnos》2013,20(2):141-142

Vertically curved, unbranched, strongly lined burrows are prominent features of muddy outer‐shelf/offshore deposits of Cretaceous to Pleistocene age. Such burrows are usually called Terebellina, but use of this ichnogenus should be avoided for two reasons: 1) the type species of Terebellina is a large agglutinated foraminiferid referable to Bathysiphon, not a trace fossil; and 2) most trace fossils identified with Terebellina are either examples of Palaeophycus (in cases where burrows are essentially horizontal and occur individually) or Schaubcylindrichnus (where burrows are oblique to stratification and occur in aggregations or loose clusters). The replacement name S. freyi is proposed for this latter category of burrow.

These light‐colored, grain‐lined burrows are conspicuous structures in the dark‐colored, outer‐shelf mudrocks of the lower Pleistocene Rio Dell Formation. The burrows are part of a typical “distal Cruziana ichnofacies”; association of structures, including Teichichnus, Planolites, Palaeophycus, and Chondrites, occurring in thoroughly bioturbated background sediments. Schaubcylindrichnus freyi in the Rio Dell is interpreted as the dwelling structure of a gregarious, endobenthic organism, comparable to the lined burrows produced by the deposit‐feeding polychaete Clymenella.  相似文献   

3.
Reproductive traits of three ocypodid crabs,Scopimera globosa, Ilyoplax pusillus andMacrophthalmus japonicus, were compared.S. globosa andI. pusillus, inhabiting the upper-middle intertidal zone, produced 1–2 large broods per year, whereasM. japonicus, inhabiting the lower intertidal zone, produced 4–5 small broods per year. InS. globosa andI. pusillus, ovigerous females remained in their plugged burrows without feeding until their eggs hatched. On the other hand, femaleM. japonicus fed actively on surface mud while incubating. We concluded that few large broods may be advantageous in crab species that incubate in burrows, whereas continuous small broods may be advantageous in species that feed actively while incubating.  相似文献   

4.
Three new ichnogenera and five new ichnospecies are described for new trace fossils of termitaria (including associated gallery systems) of subterranean termites from upper Eocene through lower Miocene rocks of northern Egypt. All but two ichnospecies (Krausichnus trompitus, ichnogen, and ichnosp. nov., and A’, altus, ichnosp. nov.) show varying degrees of affinity to nests of the extant subterranean termite species Sphaerotermes sphaerothorax (Termitidae, Macro‐termitinae).

Termitichnus qatranii (Bown, 1982) is divided into two ichnospecies, the previously named T. qatranii, and a more generalized form, T. simplicidens, ichnosp. nov. Vondrichnus obovatus, ichnogen. and ichnosp. nov., is named for simple, possibly macrotermitine nests with oblate form, and Fleaglellius pagodus, ichnogen. and ichnosp. nov., records a nest form similar to V. obovatus, but one in which successive vertical growth by chamber apposition has produced a subterranean, tower‐like structure, reminiscent of that built by extant, epigeous Cubitermes. Krausichnus trompitus, ichnogen. and ichnosp. nov., and A’, altus, ichnosp. nov., record two unique nest architectures probably produced by unknown but related species of humivorous termites. The nest architecture expressed by Krausichnus is of wholly unknown affinity and is only distantly related in form to the ichnofossils of other termite nests known from the Tertiary of Egypt.

Study of the architecture of the nests of these ancient termites reveals details important in reconstructing the phylogeny of termite nests and documents two novel blueprints for chamber expansion and society budding in what were probably primitive Macrotermi‐tinae. It also indicates that at least two constructed edifices, earlier known only as epigeous manifestations of extant termite species, were almost certainly first developed by species living underground.

The extant Macrotermitinae are a subfamily of termites originally believed to have evolved in the post‐Eocene of the Ethiopian biogeo‐graphic region. We offer fossil evidence of four distinct, possibly macrotermitine structures from upper Eocene rocks. This evidence suggests that this termite subfamily (or at least their peculiar mode of nest construction) might have evolved considerably earlier, as it is already well established and exhibits several variants by the late Eocene in Egypt.  相似文献   

5.
In a taxonomic/phylogenetic study of the genus Lenormandia, several species were found to differ significantly from the type species, L. spectabilis Sonder, in apical morphology, blade‐surface pattern, medullary construction, the presence of pseudopericentral cells, and the position of reproductive structures. These species constitute two groups that differ morphologically, a finding largely supported by analysis of 18S rRNA sequences, as reported previously. The two putative Lenormandia species from New Zealand, along with two previously undescribed species also from New Zealand, comprised one such group, designated here by the new genus name Adamsiella L.E. Phillips et W.A. Nelson, gen. nov. and including A. melchiori L.E. Phillips et W.A. Nelson, sp. nov., A. lorata L.E. Phillips et W.A. Nelson, sp. nov., A. angustifolia (Harvey) L.E. Phillips et W.A. Nelson, comb. nov., and A. chauvinii (Harvey) L.E. Phillips et W.A. Nelson comb. nov. Adamsiella differs from Lenormandia by incurved apices, a chevron surface pattern, and reproductive structures on dorsi‐ventrally flattened apically incurved polysiphonous branchlets usually produced at the margins. Two species endemic to Australia formed the second group designated by the resurrected generic name Epiglossum and also characterized by a strongly incurved apex and chevron surface pattern but with reproductive structures produced on terete polysiphonous branchlets found either on the midrib or elsewhere on the blade surface but not the margins. Epiglossum contains E. smithiae (J.D. Hooker et Harvey) Kützing and E. proliferum (C. Agardh) L.E. Phillips, comb. nov.  相似文献   

6.
The large bivalve, Panopea faujasi Ménard de la Groye, 1807 is locally abundant in shallow marine sandy facies in Late Pliocene sediments of Rhodes, where it occurs in life position within its burrow. Several Panopea‐trace fossils were sectioned in a vertical plane and others in series of horizontal sections, in order to study them in detail. Morphology of the structures produced by different individuals varied greatly, and even neighbors at the same horizon were unalike in detail. All show retrusive, upward shift in accordance with sedimentary accretion, but some also show protrusive movement as a response to erosive phases. As a response to sedimentation, the bivalve dug its way upwards by moving terrigenous grains and skeletal material from above it to below. In cross section the outline is slightly oval to circular. The longest example of these retrusive structures was preserved to a length of 86 cm and had a diameter of about 15 to 20 cm. As the bivalve has a long lifespan, and burrows deeply, the structures have good preservation potential and can reveal details of depositional history. The trace fossil is named Scalichnus phiale igen. et isp. nov.  相似文献   

7.
Bordy, E.M., Sztanó, O., Rubidge, B.S. & Bumby, A. 2010: Early Triassic vertebrate burrows from the Katberg Formation of the south‐western Karoo Basin, South Africa. Lethaia, Vol. 44, pp. 33–45. Very large (~30–35 cm), uniform diameter cylindrical burrows were found at two localities, ~100–110 m above Permo‐Triassic boundary in the fluvial Katberg Formation (main Karoo Basin, South Africa). Analysis of their morphology and stratigraphical distribution allows us to improve both the understanding of the ethology of burrowing, and also the reconstruction of the earliest Triassic ecosystems. These burrows have a single opening that leads, via a large, uniform diameter, semi‐horizontal tunnel, to a rounded terminus. These 3‐m‐long structures descend at angles of ~30° to a maximum of 1.5 m depth. They are devoid of chambers, branching, cross‐cutting, coiling or spiralling. Filled with coarse sediments, some have a <5‐mm clay lining, and most have subtle indentations and various scratch marks. These burrows were possibly excavated as resting, hiding or aestivating shelters, and are tentatively attributed to dicynodonts (i.e. Lystrosaurus murrayi and L. declivis). Data suggest that burrowing was widespread after the P/Tr boundary event, when in this part of Gondwana, dryland fluvial systems had large fluctuations in flow with extended low‐flow periods or drought punctuated by high‐discharge periods. We hypothesize that these constructed refuges played a role in the biodiversity recovery and maintenance in the Early Triassic (Induan) ecosystem. □Early Triassic, Karoo Basin, Katberg Formation, South Africa, Tetrapod Burrows.  相似文献   

8.
Abstract

A new species of Loricifera, Rugiloricus bacatus sp. nov. is described together with the diagnoses of two other Rugiloricus species, Rugiloricus sp. nov. A and B, from the Faroe Bank (North Atlantic). Characteristic for all three species is the presence of a new type of reduced larva, a ghost‐larva. This type of reduced larva was discovered in 1986 by Jeanne Renaud‐Mornant, but it was with the Faroe Bank material that it was first discovered that the ghost‐larvae belonged to the phylum Loricifera. The ghost‐larvae are eitherfound inside late instar Higgins‐larvae, called penultimate Higgins‐larvae, or in the sediment. The three types of Higgins‐larvae from the Faroe Bank can be distinguished by characters such as anterior setae, posterior setae and toes. The adults of Rugiloricus bacatus sp. nov. are characterised by a prominent ruff resembling a pearl necklace; two of the eight clavoscalids are modified in the 1st row; the 2nd row of leg‐shaped scalids are very large and robust, and the 9th row with 30 beak‐like scalids alternating with 30 alternating plates. The postlarvae are free‐living and their scalids on the introvert are reduced to protoscalids. Postlarvae and adult stages have not been found for Rugiloricus sp. nov. A and B and therefore only diagnoses of these two species are presented here.  相似文献   

9.

In coastal cliffs consisting of Pliocene fine‐grained clastic sediments at El Rompido, Huelva, Spain we discovered around the high water line an extensive zone of about 1.5 m in height burrows that were made by up to 4 mm long isopods Paragnathia formica (Hesse) and small 5 mm long staphylinid beetles (Bledius cf. corniger Rosenhauer). The burrowing zone was crowded with irregular burrows 2–5 mm in diameter and extended some 5 cm deep in the cliff. The base of the cliff showed a clear (bio)erosional notch due to this burrowing activity, comparable to those produced by marine boring and scraping organisms in, for example, calcareous rocks. This indicates that the activity of Paragnathia and Bledius helps in eroding the cliffs, a phenomenon not published earlier as far as we know. A comparable but less extensive burrowed zone was found farther upstream near Cartaya. Their presence around the high tide zone also might prove these burrows to be good markers of former high tide lines in older cliffs.  相似文献   

10.
The morphology of vegetative and reproductive structures of Martensia fragilis Harvey, Martensia australis Harvey and Martensia flabelliformis Harvey ex J. Agardh was studied based on material collected from Japan. M. fragilis and M. australis have cystocarps with terminal carposporangia, and their membranous portions are composed of cell layers with regularly stacked flat cells of similar size. M. flabelliformis has the following combination of characters: (i) carposporangia are formed in short chains; and (ii) the membranous portion is composed of irregularly arranged flat cells of various sizes. These characters are distinctly different from those of Martensia and warrant the establishment of Neomartensia gen. nov., with the type species Neomartensia flabelliformis comb. nov.  相似文献   

11.
Maemonstrilla gen. nov. , known exclusively from females, is proposed for Monstrilla longipes A. Scott, 1909, M. turgida A. Scott, 1909, and five new species from coral reef plankton in the Ryukyu Islands, Japan: Maemonstrilla hyottoko sp. nov. (type species), M. polka sp. nov. , M. spinicoxa sp. nov. , M. simplex sp. nov. and M. okame sp. nov. A syntype of M. turgida was examined, but the holotype of M. longipes is lost; the latter species, being similar to several of the new species, is regarded as unidentifiable, and the identity of specimens assigned to it by several authors is put in doubt. Until now, all known female monstrilloids have had posteriorly trailing ovigerous spines, but in Maemonstrilla gen. nov. these spines point anteriorly and hold the egg mass between the legs beneath the thorax. This is the first known instance of subthoracic brooding in a planktonic copepod; its functional significance is discussed, and brooding habits of non‐planktonic copepods are briefly reviewed. The intercoxal sclerites of legs 1–4 in Maemonstrilla gen. nov. are very wide, making room for the eggs. In all species except M. turgida comb. nov. , the inner seta of the proximal segment of each leg ramus is either absent or reduced to a nub; this may lessen interference of the egg mass with leg movement. All species have a uniramous leg 5 with two setae, except M. turgida comb. nov. (biramous with setae on both rami); M. turgida comb. nov. is evidently the sister‐group of its congeners, each sister‐group in the genus being defined by additional autapomorphies. Scanning electron micrographs of all the Ryukyuan species except M. simplex sp. nov. are provided; these constitute a preliminary survey of monstrilloid integumental organs and cuticular ornamentation. Among the unusual features are two lobes at the base of the coxa in legs 1–4 of M. polka sp. nov. and M. spinicoxa sp. nov. and two pairs of posterodorsal spine‐like scales on the first and second free pedigers of M. turgida comb. nov. Newly hatched nauplii of M. okame sp. nov. , examined by scanning electron microscopy, are generally similar to those of Monstrilla hamatapex Grygier & Ohtsuka, 1995, but with a different mandibular structure in which the distal hook and seta clearly represent the endopod, not enditic armament of the basis. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 152 , 459–506.  相似文献   

12.
Peter H. Gibson 《Ichnos》2017,24(2):83-90
This study used measurements and observations on the burrows of extant species of Dodecaceria fimbriata and D. concharum to identify their possible fossil burrows. The extant burrows were from marine littoral shale and the calcareous alga Lithothamnion. From published records unequivocal fossil burrows were not found for these two species. Trace fossils of D. fimbriata appear to have been present in the Miocene and Dodecaceria cretacea (probably not Dodecaceria) in the Cretaceous. The conclusion is that D. fimbriata and D. concharum separated from a common ancestor in the late Cretaceous.  相似文献   

13.
Synopsis Submersible dives were made on a site in the Gulf of Mexico 160 km southeast of Galveston, Texas in September 1984. Both yellowedge, Epinephelus flavolimbatus, and snowy grouper, E. niveatus, were observed utilizing shelter around rock ridge habitats. The yellowedge grouper also sought shelter within three types of burrows cut into soft sediment. Many of these burrows were significant excavations consisting of large trenches 7–8 m long, 2–3 m wide, and 1–1.5 m deep. Burrows were found in depths from 265 to 290 m. Tilefish, Lopholatilus chamaeleonticeps, also occur at this site, usually inhabiting the characteristic vertical burrows already described for this species. In four daytime submersible transects covering a linear distance of over 13000 m, we observed a total of 66 yellowedge groupers. Twenty-five were in burrows, 39 among rocks, and two over open bottom. It is suggested that this species may have an advantage over congeners that utilize only rocky habitat for cover. It may also compete for shelter with tilefish at depths where the two species overlap.Contribution No. 696, Harbor Branch Foundation, Inc. and Contribution No. 733, The University of Texas Marine Science Institute.  相似文献   

14.
Few species in the genus Grateloupia have been investigated in detail with respect to the development of the auxiliary cell ampullae before or after diploidization. In this study, we document the vegetative and reproductive structures of two new species of Grateloupia, G. taiwanensis S.‐M. Lin et H.‐Y. Liang sp. nov. and G. orientalis S.‐M. Lin et H.‐Y. Liang sp. nov., plus a third species, G. ramosissima Okamura, from Taiwan. Two distinct patterns are reported for the development of the auxiliary cell ampullae: (1) ampullae consisting of three orders of unbranched filaments that branch after diploidization of the auxiliary cell and form a pericarp together with the surrounding secondary medullary filaments (G. taiwanensis type), and (2) ampullae composed of only two orders of unbranched filaments in which only a few cells are incorporated into a basal fusion cell after diploization of the auxiliary cell and the pericarp consists almost entirely of secondary medullary filaments (G. orientalis type). G. orientalis is positioned in a large clade based on rbcL gene sequence analysis that includes the type species of Grateloupia C. Agardh 1822 , Gfilicina. G. taiwanensis clusters with a clade that includes the generitype of Phyllymenia J. Agardh 1848 , Ph. belangeri from South Africa; that of Prionitis J. Agardh 1851 , Prlanceolata from Pacific North America; and that of Pachymeniopsis Y. Yamada ex Kawab. 1954, Palanceolata from Japan. A reexamination of the type species of the genera Grateloupia, Phyllymenia, Prionitis, and Pachymeniopsis is required to clarify the generic and interspecific relationships among the species presently placed in Grateloupia.  相似文献   

15.
On the tidal flats of the island of Sylt (eastern part of the North Sea) the quantity of micro- and meiofauna associated with shoots of seagrass(Zostera noltii), with infaunal bivalves(Macoma balthica), and with tubes and burrows of polychaetes(Pygospio elegans, Pectinaria koreni, Nereis diversicolor, Nereis virens, Arenicola marina) was found to add up to 5 to 33 % of the overall abundance. These structures, taken together, account for 10 to 50 % of the faunal abundance on an average tidal flat at Sylt. The quantitative effect of biogenic structures at the sediment surface (casts and funnels) is small compared to that of tubes and burrows penetrating the anaerobic subsurface layer. In providing stable oxic microenvironments these elite structures frequently bring together more individuals than occur in the entire reducing sediment below surface. Faunal composition of irrigated dwellings of large infauna is different from that of the oxic surface sediment. The common denominator of all elite structures of the subsurface is an oxic halo. Burrows without such a halo are unattractive. There is no evidence that owners of burrows prey on their smaller inmates.  相似文献   

16.
Krapovickas, V., Mancuso, A.C., Marsicano, C.A., Domnanovich, N.S. & Schultz, C.L. 2013: Large tetrapod burrows from the Middle Triassic of Argentina: a behavioural adaptation to seasonal semi‐arid climate? Lethaia, Vol. 46, pp. 154–169. We report the discovery of large burrow casts in the early Middle Triassic Tarjados Formation, at Talampaya National Park, north‐western Argentina. Facies analysis indicates the burrows are preserved in sandbars deposited by an ephemeral river under semi‐arid and seasonal climatic conditions. The structures are mostly preserved in longitudinal cross‐section and consist of an opening, an inclined tunnel (ramp), and a terminal chamber. The ramp is 8–14 cm in height, up to 130 cm in length and penetrates 49–63 cm bellow the palaeosurface with an inclination of 22°–30°. We studied burrow cast dimensions, overall architectural morphology, surficial marks, and compared them with other large burrows of both invertebrate and vertebrate origin. A tetrapod origin of the burrow casts was established based on: distinctive architecture, and size, which is more than twice the most common size range for large terrestrial invertebrate burrows. Comparison with other Upper Permian and Triassic tetrapod burrows allows us to identify three general morphological groups: (1) simple inclined burrows; (2) helical burrows; and (3) burrow network complexes, representing different behaviours. A study of tetrapod body fossils preserved within other Upper Permian and Triassic burrows shows that the Tarjados structures were most likely produced by non‐mammalian cynodonts. The environmental and climatic context suggests that aridity and seasonality played a fundamental role selecting burrowing behaviour in therapsids and that by the Early–Middle Triassic their burrowing behaviour attained a complexity comparable to modern mammals. □Argentina, behaviour, palaeoclimate, Permo‐Triassic, Tarjados Formation, Tetrapod burrows.  相似文献   

17.
A partial rbcL sequence from the type material of Spongites discoideus from southern Argentina showed that it was distinct from rbcL sequences of South African specimens to which that name had been applied based on morpho-anatomy. A partial rbcL sequence from an original syntype specimen, herein designated the lectotype, of Lithophyllum marlothii, type locality Camps Bay, Western Cape Province, South Africa, was identical to rbcL sequences of South African field-collected specimens assigned to S. discoideus. Based on phylogenetic analyses of rbcL and/or psbA sequences, both of these species belong in Pneophyllum and are transferred there as P. discoideum comb. nov. and P. marlothii comb. nov. The two species exhibit a distinct type of development where thick, secondary, monomerous disks are produced from thin, primary, dimerous crusts. Whether this type of development represents an example of convergent evolution or is characteristic of a clade of species within Pneophyllum remains to be resolved.  相似文献   

18.
19.
A new genus of Panorpidae, Megapanorpa gen. nov. , is erected for five new species, Megapanorpa grandis sp. nov. (type species), M. absens sp. nov. , M. gaokaii sp. nov. , M. jiangorum sp. nov. and M. wanghongjiani sp. nov. This genus is similar to Cerapanorpa Gao et al., 2016 in a single anal horn on the sixth tergum of male, but can be differentiated from the latter by the following characters: the seventh abdominal segment of male is constricted and stalk‐like at base, the subgenital plate of female with a pair of lateral plates, and the medigynium of female with a concealed axis. Keys to genera of Panorpidae and species of Megapanorpa gen. nov. are presented. The morphology and function of anal horns in different genera and species have been discussed.  相似文献   

20.
Abstract: Red calcareous Middle Cambrian palaeosols from the upper Moodlatana Formation in the eastern Flinders Ranges of South Australia formed in well‐drained subhumid floodplains and include a variety of problematic fossils. The fossils are preserved like trace fossil endichnia but do not appear to be traces of burrows or other animal movement. They are here regarded as remains of sessile organisms, comparable with fungi or plants living in place, and are formally named as palaeobotanical form genera under provisions of the International Code of Botanical Nomenclature. Most common are slender (0.5–2 mm) branching filaments flanked by green‐grey reduction haloes within the red matrix of palaeosol surface horizons (Prasinema gracile gen. et sp. nov.). Other axial structures (Prasinema nodosum and P. adunatum gen. et spp. nov.) are larger and show distinctive surface irregularities (short protuberances and irregular striations, respectively). The size and form of these filaments are most like rhizines of soil‐crust lichens. Other evidence of life on land includes quilted spheroids (Erytholus globosus gen. et sp. nov.) and thallose impressions (Farghera sp. indet.), which may have been slime moulds and lichens, respectively. These distinctive fossils in Cambrian palaeosols represent communities comparable with modern biological soil crusts.  相似文献   

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