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1.
In 1849, Isaac Lea named Sauropus primaevus for footprints from Mount Carbon, Pennsylvania, USA, then the oldest fossil vertebrate footprints reported. In 1902, O. P. Hay constructed a new ichnogenus Palaeosauropus for this ichnospecies. Palaeosauropus has been one of the most frequently reported Mississippian footprint ichnogenera in North America and remains a valid ichnotaxon. The holotype of Palaeosauropus (= “Sauropus”) primaevus (referred to as P. primaevus), consisting of a single manus/pes pair, is described and illustrated in Lea (1853) Lea, I. 1853. On the fossil foot-marks in the Red Sandstones of Pottsville, Schuylkill County, Penna. Transactions of the American Philosophical Society, 10(new series): 307315.  [Google Scholar] and is housed at the Academy of Natural Sciences in Philadelphia, Pennsylvania (ANS9752). Lea's large specimen of P. primaevus (approximately 86 cm by 53 cm), that included a trackway of six manus/pes pairs, described and illustrated in 1853 and 1855, was a combination of ANS9752 and a second specimen represented by a plaster cast housed at the National Museum of Natural History (USNM487148). Historical documents and examination of the Mauch Chunk Formation at Mount Carbon, Pennsylvania, enabled the identification of Lea's tracksite, originally reported to be a few hundred feet (about 75 m) from the former Mount Carbon Hotel. Our forensic evidence indicates the type locality for P. primaevus is approximately 90 m south from the southwest corner of Centre and Main Streets in Mount Carbon, Pennsylvania, with geographical coordinates of N 40° 40' 25.7”, W 76° 11' 14.9”. The type locality is within the middle member of the Mauch Chunk Formation, a fluvial sequence of late Mississippian (Visean) Age.  相似文献   

2.
Temnocorpichnus isaacleai is a new ichnogenus and ichnospecies of temnospondyl amphibian body impression from the Mississippian (Visean) Mauch Chunk Formation of eastern Pennsylvania, United States. The shovel-shaped head, robust limbs, relatively short trunk and smooth integument diagnose the ichnotaxon and readily distinguish it from Hermundurichnus and Sauropleura, the only other named body impressions of Paleozoic tetrapods. Temnocorpichnus is a compound ichnogenus in which the footprint ichnogenus Batrachichnus is a behaviorally distinct component. The temnospondyl identity of Temnocorpichnus adds to the sparse and earliest records of temnspondyls, which are of Visean age. The smooth integument of the ichnogenus does not support the presence of ventral scales or armor in the earliest temnospondyls, but body proportions of the Mauch Chunk body impressions indicate a relatively terrestrial temnospondyl not matched by any taxon now known from bones. Three closely associated impressions of Temnocorpichnus on a single bedding plane suggest some sort of gregarious behavior in Mississippian temnospondyls and may support speculation that internal fertilization and associated courtship behavior evolved independently in one group of amphibians more than 300 million years ago.  相似文献   

3.
Palaeosauropus primaevus is a tetrapod footprint ichnotaxon first described from the Upper Mississippian (Visean) Mauch Chunk Formation near Pottsville, Pennsylvania, United States. Our relocation of the type locality and stratigraphic horizon of P. primaevus, a long-available but unstudied collection of tetrapod footprints from these strata, and our new collections allow a much fuller characterization of this ichnotaxon and the range of extramorphological variation encompassed by it. P. primaevus is characterized as the footprints of a quadruped with a pentadactyl pes and a tetradactyl manus, in which the pes frequently oversteps the manus and with which tail drags are common. In the manus, all digits are relatively broad and have rounded tips, digit III is longest, and digit IV is more widely separated from digit III than the other digits are from each other. The pes has five digits that are also wide and blunt-tipped, digit IV is longest, and digit V projects nearly laterally. P. primaevus is the track of a relatively large temnospondyl (~400 mm gleno-acetabular length) and documents the Mississippian presence of such large amphibians long before their body fossil record. Palaeosauropus also occurs in Mississippian strata in Indiana and is distinguished from the geologically younger but similar temnospondyl footprint ichnogenus Limnopus by its relatively narrower manus and pes that lack broad and rounded sole impressions.  相似文献   

4.
    
Dirk Knaust 《Ichnos》2013,20(3):178-186
Abstract

Undichna quadrisulcata isp. nov. is described from the Eocene of Spitsbergen, where it occurs together with xiphosuran (horseshoe crabs) traces in upper shoreface to foreshore deltaic sandstone. This is the first record of a marine (deltaic) Undichna from the Eocene. The trail consists of two or three pairs of paralleling sinusoidal grooves (in epirelief) or ridges (in hyporelief). Previous records of this trace fossil from the Carboniferous and Permian were assigned to U. insolentia Anderson, 1976 Anderson, A. M. 1976. Fish trails from the early Permian of South Africa. Palaeontology 19(2): 397409. [Google Scholar], which, however, comprises a more complex pattern. The repeated occurrence of U. quadrisulcata isp. nov. in the Carboniferous, Permian, Triassic and Eocene, independent from U. insolentia, justifies its own ichnospecies name and suggests a different kind of producer. U. quadrisulcata isp. nov. is interpreted as a fish trail, probably produced by a representative of Amiiformes (actinopterygian, ray-finned fish) or coelacanth fish.  相似文献   

5.
南极利文期顿岛晚三叠世复理石相遗迹化石   总被引:3,自引:0,他引:3  
南极利文斯顿岛赫德半岛中的迈尔斯陡崖组主要是浅变质的石英长石杂砂岩、粉砂岩、泥岩和粉砂岩与泥岩互层等组成的复理石,厚度可能超过3000m,形成于浊积扇的上扇和下扇部分,时代可能为晚三叠世。在复理石相岩石中发育一套深水的遗迹化石,共有15个遗迹属、16人遗变种,其中有10个可以鉴定到遗迹种,两个比较种,4个只鉴定到遗迹属,未鉴定到遗迹种,1建立1个新遗迹属及新遗迹种,除新遗迹属种外,其余14个遗迹属,15个遗迹种都曾经在深海复理石相浊积岩内发现过,其中Belorhaphe,Glockerichnus,Lophoctenium,Rhabdo-glyphus,Paleodictyon,Suborenzinia,Spirophycus,Strobilorhaphe,Tuberculicnus,Cochlichnus等,属于浊流前产生在复理石相泥岩内的高度分异的雕画迹(Graphoglyptida),它们产于泥岩却保存为上覆砂岩底面的铸型凸起。别外,Fucusopsis和Neonereites却产生在砂岩内代表浊流后形成的沉积后遗迹组合,文内还描述3种浊流常见的无机构造,并上上述遗迹化石进行比较。  相似文献   

6.
Summary Rhythmically laminated fine-grained lacustrine carbonatcs of the Cretaceous La Huérguina Limestone Formation at Las Hoyas fossil site, central Spain, contain not only a spectacular body fossil fauna, but also vertebrate and invertebrate trace fossils. The study of the Las Hoyas invertebrate ichnofauna provides valuable taphonomic, paleoecological and paleoenvironmental information and represents one of the first attempts to study in detail a lacustrine trace-fossil assemblage in carbonate rocks. The Las Hoyas ichnofauna includesCruziana problematica, Helminthoidichnites tenuis, Lockeia isp.,Palaeophycus tubularis, andTreptichnus pollardi. This assemblage is characterized by low ichnodiversity and small burrow size, and it is dominated by surface trails and extremely shallow burrows produced mostly by detritus feeders. The Las Hoyas ichnofauna indicates low to moderately low energy, permanently submerged, shallow-lacustrine areas. The ichnofauna is suggestive of environmental stress, most likely oxygen-depleted conditions in interstitial waters. Occurrence of traces in event beds indicates opportunistic colonization by epifauna and very shallow infauna during brief periods of improved oxygenation related to the passage of density underflows and dilute turbidity currents. The Las Hoyas ichnofauna resembles other shallow lacustrine trace-fossil assemblages of the archetypalMermia ichnofacies and differs significantly from the archetypalScoyenia ichnofacies. It is therefore best regarded as a proximal, depauperate example of theMermia ichnofacies. The Las Hoyas assemblage is similar to the slightly older lacustrine Montsec ichnofauna, but it is remarkably different from marine ichnocoenoses of other Mesozoickonservat-lagerst?tten in lithographic limestones such as those of Cerin, Solnhofen and Nusplingen.  相似文献   

7.
A remarkable specimen of a compound trace fossil in Pennsylvanian sandstone comprises three very different ichnotaxa in conjunction: Protovirgularia dichotoma, Lockeia siliquaria and Lophoctenium isp. The combined activities represented by these ichnotaxa reflect the locomotion, resting and feeding behavior of a cleft-foot, protobranch clam (bivalve) that burrowed through the sediment, paused five times to deposit-feed, and then burrowed on to a new location, possibly as a reaction to a depositional event. It is estimated that the complete trace fossil was made in 24 hours or less. The three ichnotaxa also provide morphologic details of the bivalve's shell and soft parts (foot and labial palps).  相似文献   

8.
The clastic Horlick Formation contains an ichnofauna of 28 ichnotaxa dominated by burrowers. These are a mixture of simple vertical forms (Skolithos linearis, S. magnus, Bergaueria cf. langi, Rosselia socialis, Monocraterion isp.), U or arc-like forms (Diplocraterion parallelum, Arenicolites types A and B, Catenarichnus antarcticus, C. isp., aff. Lanicoidichna isp.), and complex, vertical spiral structures (Asterosoma isp., Spirophyton isp.). Horizontal burrows include Ancorichnus cf. capronus, Palaeophycus tubularis, and Psammichnites devonicus isp. nov. Surface traces comprise Haplotichnus isp., Cruziana problematica, C. rhenana, Rusophycus aff. carbonarius, R. isp., Protovirgularia rugosa, Lockeia ornata and cubichnia indet., while trackways include Diplichnites gouldi, D. isp., Maculichna? isp. and large imprints. The Horlick Formation (maximum 56 m) records an early Devonian transgression onto a deeply weathered land area that lay in the direction of Marie Byrd Land, spreading from the South Africa sector of Gondwana. Analysis of the trace fossils confirms their formation in near-shore to intertidal environments, with some ichnotaxa living close to the marine/fluvial boundary (e.g., Spirophyton, aff. Lanicoidichna, Cruziana problematica, Rusophycus aff. carbonarius, Maculichna?). The ichnofauna probably comprised a variety of marine suspension and deposit-feeding worms, shallow burrowing molluscs (bivalves and possibly bellerophontids) and several different types of arthropods, including trilobites.  相似文献   

9.
    
Topological fidelity of metazoan traces formed by metazoan behaviour is little influenced by compaction, diagenesis, continuous soft-sediment deformation and biostratinomy, substrate consistency, etc., whereas all of these can greatly alter the Euclidean geometric attributes of metazoan traces. Morphological characteristics of trace fossils can be distinguished and described objectively by both topological and Euclidean geometric parameters. The former constitute the basis of ichnoorder and ichnofamily. On the basis of topological criteria, metazoan traces can be classified as 4 ichnoorders and 22 ichnofamilies, consisting of 9 basic and 3 combined topological configurations. At a topological level, the behavioural diversity and complexity indicated by metazoan topoichnotaxa remain fairly stable in the Phanerozoic. All ichnoorders, 75% of ichnofamilies and all 9 basic topological configurations of metazoan traces are formed in the late Neoproterozoic, and all ichnofamilies, a combination of topological configurations and the most complex and highest level of topological configurations of metazoan traces, occurred in the early Cambrian. The evolution of metazoan traces can be expressed in three ranks. Changes at ichnoorder level constitute the first evolution, which is associated with the advent of kingdoms (animalia and plantae, etc.) and phyla (Ediacara and bilaterian, etc.), and the first level of palaeoecological and palaeoenvironmental changes, such as the appearance or disappearance of an ecosystem (Precambrian biomat). The first evolution terminated in the late Neoproterozoic. Changes at the ichnofamily level constitute the second evolution, which is associated with the advent of important phyla such as coelomate animal explosion and the second level of palaeoecological and palaeoenvironmental changes, such as structural changes within an ecosystem. The second evolution terminated in the early Cambrian. Changes at the ichnogeneric and ichnospecific levels constitute the third evolution, which is associated with the appearance or disappearance of the organic taxa lower than phylum, such as dinosaurs and birds, etc., and the third and fourth levels of palaeoecological and palaeoenvironmental changes, such as community-type level changes, within an established ecological structure and community level. The third evolution has been taking place since the Proterozoic.  相似文献   

10.
林巍  要乐  黄兴 《古生物学报》2022,61(3):439-457
石炭纪密西西比亚纪是四射珊瑚相对繁盛的时期。维宪晚期至谢尔普霍夫期, 受晚古生代大冰期和海西运动的影响, 西欧等不少地区的海相沉积发生相变, 四射珊瑚记录稀少。华南在此时仍广泛发育浅海相碳酸盐岩沉积, 含有丰富的四射珊瑚化石记录。通过对安徽省巢湖地区和州组四射珊瑚的研究, 共鉴定出11属15个种, 其中包含2比较种1、亲近种和3未定种。珊瑚动物群面貌具有典型华南大塘晚期四射珊瑚的特征, 属于Aulina rotiformis带(原Yuanophyllum带上部), 年代为谢尔普霍夫期。和州组的四射珊瑚组合可与湘中梓门桥组上部 Yuanophyllum带的Neoclisiophyllum yengtzeense–Koninckophyllum stellatum亚带和Lophophyllum lophyphylloidea亚带对比 , 也可与黔西赵家山组的 Palaeosmillia murchisoni murchisoni 组合带和 Lithostrotion decipiens–Dibunophyllum bipartitum组合带对比。根据珊瑚动物群的组成、生长形态、共生关系和围岩的岩性特征, 可判断动物群生活在相对浑浊、局限、富营养化的近岸浅海环境中。  相似文献   

11.
Robert Metz 《Ichnos》2013,20(4):190-193
Offshore marine deposits of hemipelagic dark-gray shales comprising the Middle Devonian Mahantango Formation have yielded the first evidence of the trace fossil Paleodictyon from Pennsylvania. Paleodictyon occurs in conjunction with a diversity of largely deposit-feeding trace fossils belonging to the Cruziana ichnofacies, and documents another example of a shallower-water occurrence of this ichnofossil in Paleozoic rocks.  相似文献   

12.
Robert Metz 《Ichnos》2013,20(4):253-266
Lake‐margin deposits of the Late Triassic Passaic Formation, Douglassville, Pennsylvania, have yielded a moderate variety of trace fossils. The greatest diversity and abundance of trace fossils occurs on the sole of a thin gray claystone overlain and underlain by gray siltstones. Specimens of Cochlichnus anguineus, Helminthoidichnites tenuis, Helminthopsis hieroglyphica, Treptichnus pollardi, and paired trails reflect simple, unspecialized, horizontal grazing as well as feeding traces under very shallow water lacustrine conditions. The lack of commonly associated Scoyenia burrows in these deposits may possibly be related to the degree of maturation of the organic debris available. The traces, as well as a lack of meniscate burrows, compare favorably to the Mermia ichnofacies, except Passaic deposits exhibit evidence of subaerial exposure. This unit most likely records a lacustrine expansion whereby grazing trails were emplaced under fully subaqueous conditions. Subsequent shallowing and desiccation, followed by sediment influx during rainstorms, favored preservation of these traces.

In contrast, the Scoyenia ichnofacies consists of feeding burrows of Scoyenia gracilis and Spongeliomorpha milfordensis within reddish brown siltstones and mud‐stones (redbed sequence). The Scoyenia ichnofacies records limited exploitation, by opportunistic infaunal deposit feeders, of lake‐margin nutrients carried in during occasional rainstorms that punctuated otherwise extended periods of aridity.  相似文献   

13.
    
Earlier weaning has often been suggested as a cause for population growth after the evolution of food production. However, evidence for weaning-time reduction is largely circumstantial. Collagen stable nitrogen- and carbon-isotope ratios from juvenile and adult burials from four sites in eastern North America were measured to estimate weaning onsets and durations before and after the appearance of intensive food production. Two preagricultural Late Archaic sites (Indian Knoll and Carlston Annis) are compared with two highly agricultural Middle Mississippian sites (Angel and Tinsley Hill). Isotopic data and paleodemographic measures of birth rates provide no evidence for changes in weaning behavior or fertility with the development of food production in the prehistoric Lower Ohio Valley. Birth rates and weaning behavior appear to have been roughly the same at all four sites. These results indicate that models attributing population growth after the appearance of food production to earlier weaning are not universally applicable.  相似文献   

14.
    
《Palaeoworld》2020,29(3):453-461
A new exceptionally-preserved Cambrian biota, with fossils belonging to multiple phyla, has recently been found from the middle part of the Longha Formation, near Fulu Village, southeastern Yunnan, South China, and is named the Fulu biota. Groups recovered so far include polymerid trilobites, agnostoids, large bivalved arthropods, bradoriid arthropods, echinoderms, brachiopods, priapulids (worms), hyoliths, macroscopic algae, and trace fossils. The arthropods dominate the biota and are highly diverse with echinoderms second in diversity. The associated agnostoids provide a precise late Guzhangian Age (late Miaolingian Epoch) for the biota, indicating that the biota occurs stratigraphically about halfway between the occurrences of the Kaili and the Guole biotas of South China, from both of which the new Fulu biota differs significantly in faunal components. Guzhangian biotas preserving poorly mineralized tissues and complete echinoderms have been previously unknown in Gondwana until now; thus, the discovery of Fulu biota provides a unique window into life at this critical time interval.  相似文献   

15.
Summary Bored clasts occur in Eocene conglomerates deposited in the upper shoreface and beachface settings of the Dinaric foreland basin. The trace fossil assemblage consists ofGastrochaenolites, Trypanites, and possibly some other ichnotaxa and may be compared to theTrypanites Ichnofacies. The preservation characteristics of the borings reflect many stages of colonisation/boring and abrasion. The removal of shells of the boring bivalves, the different depths of the abrasional truncation of borings, and the predominant preservation of the largest excavations (Gastrochaenolites) in the ichnocoenosis are related to repeated phases of abrasion, caused by the mobility of clasts. Coastal gravel is a specific variant of hard substrates, whose mobility controls the colonisation of borers, the type of assemblage and its preservation potential.  相似文献   

16.
Summary Numerous gutter-like furrows, up to 60 cm wide and up to 9 m long are preserved at the interface “Macrocephalus Beds”/“Callovian Marl” over a surface of 20 by 200 m. They are interpreted as feeding traces made by large marine vertebrates, most likely plesiosaurs and ichthyosaurs searching for food in the lime mud of the shallow Middle Jurassic sea floor. Possible prey animals were infaunal invertebrates (crustaceans) which produced an intricate meshwork of burrows (mainlyRhizocorallium irregulare andThalassinoides) in the bottom sediments, as well as infaunal bivalves. Evidence from cololites of predatory pelagic reptiles (ichthyosaurs, plesiosaurs) as well as reptile regurgitalites indicate that these animals fed not only on fast-swimming vertebrates and cephalopods but also on epi- and endobenthic invertebrates. In addition, the cololites show that the predators ingested considerable amounts of bottom sediment. Different sizes and shapes of the traces suggest that the gutters were produced by different reptiles or age groups. Candidates for the widest gutters are pliosaurs. Of the marine vertebrates known from Jurassic time, only the snout of adult pliosaurs of the genusLiopleurodon was broad enough to produce gutters more than 40 cm wide. Smaller, less than 15 cm wide gutters, could have been made by plesiosauroids or by the narrow pointed snouts of ichthyosaurs. Almost identical traces described from the Oxfordian of Spain and similar but smaller traces from the Lower Devonian of Prague are equally interpreted as feeding traces on the sea floor. Feeding traces of vertebrates in bottom sediments may give detailed information on the hunting behaviour of the predators. However, the attribution of the traces to definite vertebrate taxa remains uncertain.
  相似文献   

17.
Canonical variate analysis and generalized distances are commonly used multivariate statistical techniques for assessing the comparative morphology of living and fossil primates. Some common pitfalls of these methods when used to analyze fossil specimens are: (1) ignoring the possibility that a fossil belongs to a group other than one of the predefined reference samples (i.e., restricted versus unrestricted approaches to classification), (2) misinterpreting probabilities of group membership (i.e., posterior versus typicality probabilities), and (3) failing to understand how sample sizes influence multivariate ordinations in trying to effectively illustrate the morphometric affinities of a fossil (i.e., weighted versus unweighted analyses with fossils entered indirectly or directly into the analysis). To better understand canonincal variate analysis and generalized distances, the workings of these methods are portrayed graphically as a series of rotations and rescaling of data plotted in a multivariate data space. The influence of sample sizes and the importance of higher-numberer canonical variates are emphasized. Simple examples taken from the literature illustrate how the different approaches to including a fosil in canonical variate analysis may affect the multivariate results upon which physical anthropologists base their interpretations of the fossil's morphology.  相似文献   

18.
A 19 m thick package of well-sorted lowermost Jurassic (Hettangian-Lower Sinemurian?) sandstones within the Shemshak Formation of the southeastern Alborz Mountains displays features characteristic of foreshore to upper shoreface environments such as tabular bedding, low-angle lamination, trough cross-stratification, parting lineation, and oscillation ripples. In contrast to most other beach successions recorded in the literature the sandstones contain a trace fossil assemblage characterised by low abundance but comparatively high diversity. The assemblage, comprising 14 ichnotaxa, is dominated by Palaeophycus heberti, Rhizocorallium irregulare, Gyrochorte comosa, and Parahaentzschelinia surlyki. Contrary to predictions, which assume a dominance of suspension-feeders in such high-energy environments, the trace fossil assemblage represents a variety of ethological groups ranging from suspension-feeders to deposit-feeders, detritus-feeders, scavengers, and a possible trap constructor (Ctenopholeus), whereby deposit-feeders predominate. This anomaly is explained by a high amount of organic detritus in the sediment, indicated by abundant plant material, and a position of the beach in the vicinity of a river mouth.  相似文献   

19.
三门峡地区含哺乳动物化石的几个第四纪剖面   总被引:2,自引:0,他引:2  
黄河三门峡地区的晚新生代哺乳动物化石包括了上新世至晚更新世各个层位,其中以早更新世的材料较多,有七种与泥河湾动物群是相同种;有4种与山西榆社、临猗和西侯度等地点的早更新世动物群是相同种。这说明三门峡地区早更新世动物群相当于维拉方晚期或中晚期。三门系属河湖沉积,但比黄河发育的历史为早,而黄河的沉积系贾福海等划分的第5层。为此,黄河形成的时间恐怕是早更新世之末或中更新世之初。  相似文献   

20.
秦岭东段李官桥盆地始新世哺乳动物化石新材料   总被引:2,自引:6,他引:2  
李官桥盆地是始新世地层发育较全、哺乳动物化石丰富的盆地。本文报道了该盆地两个始新世化石新地点,哺乳动物共计4目7属8种。其中有5个新种,分别为Kuanchuanius? danjiangensis sp. nov.、Asiocoryphodon progressivus sp. nov.、Gobiatherium minutunz sp. nov.、Lophialetes? primus sp. nov.、Eomoropus? zhanggouensis sp. nov.。动物群的时代可能为中始新世早期。  相似文献   

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