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Organic-walled microfossils from the Ediacaran Sete Lagoas Formation, Bambuí Group, Southeast Brazil: taxonomic and biostratigraphic analyses J. Paleontol (IF 1.4) Pub Date : 2024-03-18 Matheus Denezine, Dermeval Aparecido do Carmo, Shuhai Xiao, Qing Tang, Vladmir Sergeev, Alysson Fernandes Mazoni, Carolina Zabini
This work presents a detailed taxonomic study on organic-walled microfossils from the Ediacaran Sete Lagoas Formation (Bambuí Group) at the Barreiro section in the Januária area of the São Francisco basin, Brazil. Seven species are described, including Siphonophycus robustum (Schopf, 1968), Ghoshia januarensis new species, Leiosphaeridia crassa (Naumova, 1949), Leiosphaeridia jacutica (Timofeev, 1966)
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Covariable changes of septal spacing and conch shape during early ontogeny: a common characteristic between Perisphinctina and Ancyloceratina (Ammonoidea, Cephalopoda) J. Paleontol (IF 1.4) Pub Date : 2024-03-15 Yutaro Nishino, Keisuke Komazaki, Masaki Arai, Ai Hattori, Yuji Uoya, Takahiro Iida, Ryoji Wani
We analyzed the ontogenetic trajectories of conch morphology and septal spacing between successive chambers in Cretaceous ammonoids (suborders Perisphinctina and Ancyloceratina) collected from southern India, Madagascar, and Japan. All examined species, except for the family Collignoniceratidae, exhibited similar characteristics during early ontogeny. The common ontogenetic trajectories of septal spacing
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The Tropidoleptus carinatus controversy: Did this brachiopod occur in the Devonian of the Paraná Basin, Brazil? J. Paleontol (IF 1.4) Pub Date : 2024-03-06 Roberto Videira-Santos, Sandro Marcelo Scheffler
Tropidoleptus is a brachiopod genus with a very peculiar morphology that existed throughout the Devonian as a cosmopolitan taxon. Although there have been reports of the presence of this genus in the Paraná Basin since the nineteenth century, its actual occurrence has been the subject of much debate. The objective of this paper was to clarify this situation. For this purpose, dozens of specimens from
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An Edgewood-type Hirnantian fauna from the Mackenzie Mountains, northwestern margin of Laurentia J. Paleontol (IF 1.4) Pub Date : 2024-02-27 Jisuo Jin, David A.T. Harper
Silicified brachiopods from Hirnantian strata in three sections of the lower Whittaker Formation, Mackenzie Mountains, northwestern Canada, yielded a moderately diverse, Edgewood-type Hirnantian fauna, consisting of 13 species: Biparetis paucirugosus, Brevilamnulella laevis, Dalmanella edgewoodensis, Drabovia noixella, Eospirigerina putilla, Epitomyonia paucitropida, Epitomyonia sekwiensis, Glyptorthis
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Trilobites from the Al Rose Formation (Lower Ordovician, Inyo Mountains, California)—faunas marginal to the Great Basin J. Paleontol (IF 1.4) Pub Date : 2024-02-16 Richard A. Fortey, Ernesto E. Vargas-Parra, Mary L. Droser
The Lower Ordovician (Floian) Al Rose Formation from the Inyo Mountains, California, is a deeper-water, graptolitic equivalent of the well-known and richly fossiliferous successions described from Utah and Nevada. It is considered to have been originally marginal to the Laurentian paleocontinent. It has yielded a low-diversity trilobite fauna that differs strikingly from contemporary faunas to the
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A new genus and species of cornulitid tubeworm from the Hirnantian (Late Ordovician) of Estonia J. Paleontol (IF 1.4) Pub Date : 2024-02-12 Olev Vinn, Mark A. Wilson, Ursula Toom
A new cornulitid genus and species, Porkuniconchus fragilis new genus and species, is here described from the Ärina Formation (Hirnantian, Porkuni Regional Stage) of northern Estonia. This new taxon differs from most cornulitids by having a fusiform ornamentation pattern that is somewhat similar to that of Kolihaia. All studied specimens are attached to a carbonate hardground. The hardground fauna
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Cisuralian–Guadalupian brachiopod assemblages from the northern Tengchong Block in western Yunnan, China and their paleogeographical implications—a revisit J. Paleontol (IF 1.4) Pub Date : 2024-02-08 Pu Zong, Lipei Zhan, Sangmin Lee, Hao Huang, G.R. Shi, Xiaochi Jin
The early to middle Permian brachiopods from the Tengchong Block in western Yunnan, southwestern China, play important roles in biostratigraphic correlation and paleogeographic inferences of tectonic units on eastern peri-Gondwana. However, detailed taxonomic studies of these brachiopods have been limited. In this paper, we provide the systematic description of three Permian brachiopod assemblages
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Type material of Paraconularia planicostata (Dawson) from the Upper Mississippian of Nova Scotia, Atlantic Canada J. Paleontol (IF 1.4) Pub Date : 2024-01-29 Heyo Van Iten, Mo Snyder, Victor P. Tollerton
Paraconularia planicostata (Dawson, 1868) is one of two species in this genus (Sinclair, 1940) of conulariid cnidarian currently known from Mississippian strata in the Maritimes Basin in Atlantic Canada (Babcock and Feldmann, 1986). A salient characteristic of the species is the presence of a low and narrow internal carina at or near the longitudinal midline of each of the four faces of the gently
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Cambrian trilobites and associated fossils from the Uinta Mountains of Utah (USA) J. Paleontol (IF 1.4) Pub Date : 2024-01-25 John R. Foster, Frederick A. Sundberg, James W. Hagadorn
Fossils are rare in Cambrian strata of the Uinta Mountains of northeastern Utah, and are important because they can help integrate our understanding of laterally adjacent but discontiguous rock units, e. g., the Tintic Quartzite of Utah and the Lodore Formation of Utah-Colorado. New body fossils from strata previously mapped as Tintic or Cambrian Undifferentiated, but here interpreted as the Ophir
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Jurassic Trigoniida (Bivalvia) from Gebel Maghara, northern Sinai, Egypt J. Paleontol (IF 1.4) Pub Date : 2024-01-25 Wagih S. Ayoub-Hannaa, Michael R. Cooper, Ahmed A. Abdelhady, Franz T. Fürsich
The Jurassic trigoniid bivalves of Gebel Maghara, northern Sinai, Egypt are described and figured. They belong to 14 species, nine genera, and two families. The identified taxa occur in rocks ranging in age from the Toarcian (Lower Jurassic) to the lower Kimmeridgian (Upper Jurassic). Five genera and one species are new: Magharitrigonia asymmetrica new genus new species; Cotswoldella aff. C. hemisphaerica
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New material of Lophiparamys debequensis from the Willwood Formation (early Eocene) of Wyoming, including the first postcrania of the genus J. Paleontol (IF 1.4) Pub Date : 2024-01-24 Shawn P. Zack, Tonya A. Penkrot
We report new material of the rare early Eocene rodent Lophiparamys debequensis Wood, 1962 from the Willwood Formation of the southern Bighorn Basin, north-central Wyoming. The new material constitutes the first record of L. debequensis from the Bighorn Basin and documents aspects of the anatomy of Lophiparamys that were previously unknown, including a portion of the maxilla and a portion of the tarsus
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First occurrence of well-preserved Ordovician trilobites of the family Olenidae from Africa J. Paleontol (IF 1.4) Pub Date : 2024-01-15 Melanie J. Hopkins, Juan Carlos Gutiérrez-Marco, Gianpaolo Di Silvestro
Here we describe the first articulated olenid trilobite specimens recovered from the lowermost Fezouata Shale Formation (lower Tremadocian, Ordovician) of Morocco. Prior to the discovery of this sample, only two partial olenid trilobite specimens had been found from this part of the rock record. The specimens are well preserved enough to confidently identify as Leptoplastides salteri (Callaway, 1877)
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The Neogondolella constricta (Mosher and Clark, 1965) group in the Middle Triassic of North America: speciation and distribution J. Paleontol (IF 1.4) Pub Date : 2024-01-15 Michael J. Orchard, Martyn L. Golding
Neogondolella constricta (Mosher and Clark, 1965) from the Prida Formation at Fossil Hill in central Nevada was the first conodont described from Middle Triassic strata in North America. The species has since been widely reported from elsewhere despite uncertainties about its taxonomic scope and that of similar related taxa. Poor definition of these taxa has spawned a diverse nomenclature and inhibited
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Putting a crinoid on a stalk: new evidence on the Devonian diplobathrid camerate Monstrocrinus J. Paleontol (IF 1.4) Pub Date : 2024-01-15 Jan Bohatý, Markus J. Poschmann, Peter Müller, William I. Ausich
The diplobathrid camerate crinoid genus Monstrocrinus is morphologically reinterpreted on the basis of new finds from the upper Emsian (Lower Devonian) to lower Eifelian (Middle Devonian) of Germany (Rhenish Slate Mountains, North Rhine-Westphalia, and Rhineland-Palatinate). The most complete, new specimen has a long segment of column projecting outward from the basal concavity, which confirms that
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The trilobite assemblage of the Declivolithus Fauna (lower Katian, Ordovician) of Morocco: a review with new data J. Paleontol (IF 1.4) Pub Date : 2024-01-15 Sofia Pereira, Isabel Rábano, Juan Carlos Gutiérrez-Marco
Intense commercial exploitation of fossils in the famous El Qaid Errami area in the last 20 years has led to the discovery of the interesting Declivolithus Fauna in the Moroccan Anti-Atlas. This unusually large trinucleid trilobite, described originally from the Czech Republic, is the most conspicuous element of an assemblage mainly occurring in the Bofloss locality, a local biofacies development of
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Cambrian trilobites from the Nounan Dolomite and lower St. Charles Formation (upper Marjuman to lower Sunwaptan; Miaolingian to Furongian Series), Smithfield Canyon, northern Utah J. Paleontol (IF 1.4) Pub Date : 2024-01-10 Frederick A. Sundberg, Hannah R. Cothren, Carol M. Dehler
The trilobite faunas that occur with the Steptoean Positive Isotope Carbon Excursion (SPICE) at Smithfield Canyon, Utah, have been reported, but not illustrated. Given the importance of the SPICE at this section for international correlations, the trilobites from new collections from the upper Nounan Dolomite to lower St. Charles Formation at Smithfield Canyon are reported herein and integrated with
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Echericetus novellus n. gen. n. sp. (Cetacea, Mysticeti, Eomysticetidae), an Oligocene baleen whale from Baja California Sur, Mexico J. Paleontol (IF 1.4) Pub Date : 2024-01-03 Atzcalli Ehécatl Hernández-Cisneros, Tobias Schwennicke, Heriberto Rochín-Bañaga, Cheng-Hsiu Tsai
Among the several evolutionary lineages of the baleen whales (Mysticeti), the eomysticetids are an ancient successful family that retain possibly nonfunctional teeth and functional baleen, a transitional stage between toothed and baleen-assisted filter-feeding mysticetes. The patchy fossil record leaves gaps in eomysticetid paleobiology interpretations, but their diversity and widespread geographical
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A new eryopid temnospondyl from the Carboniferous–Permian boundary of Germany J. Paleontol (IF 1.4) Pub Date : 2024-01-03 Ralf Werneburg, Florian Witzmann, Larry Rinehart, Jan Fischer, Sebastian Voigt
A new eryopid temnospondyl, Stenokranio boldi n. gen. n. sp. is described based on well-preserved cranial and postcranial material from fluvio-lacustrine deposits of the Permo-Carboniferous (Gzhelian/Asselian) Remigiusberg Formation at the Remigiusberg quarry near Kusel, Saar–Nahe Basin, southwest Germany. The new taxon is characterized by three autapomorphies within the Eryopidae: (1) the relatively
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Species discrimination in the multituberculate Mesodma Jepsen, 1940 (Mammalia, Allotheria): considerations of size, shape, and form J. Paleontol (IF 1.4) Pub Date : 2024-01-03 Austin J. Ashbaugh, Craig S. Scott, Gregory P. Wilson Mantilla, Jessica M. Theodor
Although knowledge of their fossil record continues to improve, multituberculates nonetheless remain one of the more poorly understood mammalian clades, which can be attributed to a record comprised of isolated teeth and fragmentary jaws. Fortunately, the p4 of multituberculates is the most common form of remains for this group and is a principal source of diagnostic characters in systematic studies
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Faunal and paleoenvironmental changes at a Cambrian (Jiangshanian; Steptoean–Sunwaptan boundary interval) trilobite extinction event, in contrasting deep- and shallow-subtidal settings, Nevada and Oklahoma J. Paleontol (IF 1.4) Pub Date : 2023-12-27 Stephen R. Westrop, Katie F. Welch, Michael H. Engel, Jonathan M. Adrain
Successions in Oklahoma and Nevada record trilobite extinction and replacement near the Steptoean–Sunwaptan boundary in inner-shelf and outer-shelf settings, respectively. Prior to the extinctions, different trilobite biofacies occupied these environments, but faunas became similar in composition across the environmental gradient in the overlying I. “major” and Taenicephalus zones. Faunal changes in
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The late Miocene Erinaceidae and Dimylidae (Eulipotyphla, Mammalia) from the Pannonian region, Slovakia J. Paleontol (IF 1.4) Pub Date : 2023-12-21 Florentin Cailleux, Lars W. van den Hoek Ostende, Peter Joniak
The families Erinaceidae and Dimylidae are represented in the late Miocene localities of Slovakia (Borský Svätý Jur, Krásno, Pezinok, Šalgovce, Studienka, and Triblavina) by at least six hedgehog species—‘Schizogalerix’ voesendorfensis (Rabeder, 1973); Schizogalerix cf. S. moedlingensis (Rabeder, 1973); Lantanotherium sanmigueli Villalta and Crusafont, 1944; Atelerix cf. A. depereti Mein and Ginsburg
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A large pelagic lobopodian from the Cambrian Pioche Shale of Nevada J. Paleontol (IF 1.4) Pub Date : 2023-12-13 Christian R.A. McCall
Lobopodians are an iconic and diverse group of animals from the Cambrian, which alongside radiodonts, present an important window into the evolution of arthropods and the development of Paleozoic ecosystems. Of these, a rare few species outside of Radiodonta possess lateral swimming flaps. The recent discovery of Utahnax provided much-needed insight into the evolution of swimming flaps, suggesting
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New findings of Decapoda (Crustacea) in the Callovian of the Ryazan region (Central European Russia) J. Paleontol (IF 1.4) Pub Date : 2023-12-13 Ivan A. Dadykin, Alexey S. Shmakov
The decapod crustaceans of Central European Russia have been the subject of studies since the nineteenth century, and the only species, Eryma quadriverrucatum Trautschold, 1866 (Erymidae), has been found in the Callovian to the Oxfordian of that region. The present paper discusses the new exceptional findings of Solenoceridae, Glypheidae, and Mecochiridae from the upper Callovian sites of the Ryazan
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A Silurian (Homerian) pelmatozoan echinoderm fauna from west-central Ohio, USA J. Paleontol (IF 1.4) Pub Date : 2023-12-13 William I. Ausich, Chuck Ciampaglio, Alexander J. Fabian, Jeremy R. Myers
A diverse echinoderm fauna lived in reef and non-reef Silurian facies of the upper Midwestern USA. However, these faunas are dominantly preserved in dolostones with moldic preservation, and fossils from dolostone facies have not been documented to the extent of Silurian crinoids in nondolostone strata. Herein, an echinoderm fauna is described from the dolostones of the Cedarville Member of the Laurel
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Characterization of the West Siberian lineage of zokors (Mammalia, Rodentia, Spalacidae, Myospalacinae) and divergence in molar development J. Paleontol (IF 1.4) Pub Date : 2023-12-04 Semion E. Golovanov, Vladimir S. Zazhigin
Zokors (Myospalacinae) continue to be the center of systematics discussions. Phylogenetic schemes based on molecular data do not always agree with each other, nor can phylogenetic schemes based on paleontological material be complete due to the only-partial description of West Siberian zokors. This paper tries to fill this gap and presents a description of the West Siberian lineage from the late early
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A hydrozoan from the eurypterid-dominated Silurian Bertie Group Lagerstätten of North America J. Paleontol (IF 1.4) Pub Date : 2023-12-01 Evelyn Larson, Derek E.G. Briggs
Fossil capitate hydrozoans require exceptional conditions for preservation. Here we describe Bertratis ciurcae new genus, new species from the Silurian (Pridoli) of southern Ontario and upper New York State, where it occurs in association with a diverse assemblage of eurypterids. Only the float (pneumatophore) is well preserved, surviving as a thick carbonaceous compression. The new taxon is the largest
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A reappraisal of Nemavermes mackeei from the Mazon Creek fossil site expands Carboniferous cyclostome diversity J. Paleontol (IF 1.4) Pub Date : 2023-12-01 Victoria E. McCoy, Jack Wittry, Hamed Sadabadi, Paul Mayer
Nemavermes mackeei Schram, 1973, found in the Mazon Creek fossil site and the Bear Gulch Limestone, was described initially as a free-living marine nematode. Here we investigate 13 specimens of N. mackeei from the Mazon Creek to reassess its morphology and identity, and also two specimens originally identified as Gilpichthys greenei Bardack and Richardson, 1977. Based on the extensive morphological
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Corals and a cephalopod from the Whirlpool Formation (latest Ordovician, Hirnantian), Hamilton, Ontario: biostratigraphic and biogeographic significance J. Paleontol (IF 1.4) Pub Date : 2023-09-28 Robert J. Elias, Roger A. Hewitt
Solitary rugose corals assigned to Streptelasma rutkae n. sp. and an annulated orthoconic cephalopod identified as Gorbyoceras sp. occur in nearshore shallow-marine sandstone of the Whirlpool Formation in Hamilton, southern Ontario. They are the first macrofossils contributing to a modern understanding of the age and correlation of this stratigraphic unit. Streptelasma rutkae most closely resembles
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Early Eocene fossils elucidate the evolutionary history of the Charadriiformes (shorebirds and allies) J. Paleontol (IF 1.4) Pub Date : 2023-09-22 Gerald Mayr, Andrew C. Kitchener
We report charadriiform and charadriiform-like birds from the early Eocene London Clay of Walton-on-the-Naze (Essex, UK). A partial skeleton of a small modern-type charadriiform is described as a new species, Charadriisimilis essexensis n. gen. n. sp., and most closely resembles taxa of the Charadrii (plovers, stilts, oystercatchers, and other “wader-like” shorebirds). Affinities to this clade were
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The heterobranch subgenus Trochactaeon (Trochactaeon) in the Campanian (Late Cretaceous) of the northern Arabian Platform and its paleoenvironmental and paleobiogeographic implications J. Paleontol (IF 1.4) Pub Date : 2023-09-08 Izzet Hoşgör, Ismail Ö. Yılmaz, Sacit Özer
Acteonellids were one of the most significant groups of marine macro-invertebrates in the Late Cretaceous biota of the Tethyan Realm. They were common faunal elements associated with Cretaceous carbonate platform communities most notable for their abundance of rudist frameworks and thrived in coeval lagoons. The Upper Cretaceous fossil-bearing Karababa Formation, cropping out in southeastern Turkey
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Elongate Ediacaran fronds from the Flinders Ranges, South Australia J. Paleontol (IF 1.4) Pub Date : 2023-09-07 Kelsey F. Grimes, Guy M. Narbonne, James G. Gehling, Peter W. Trusler, T. Alexander Dececchi
Decimeter-scale, elongate, fossil fronds from the Ediacara Range in South Australia were formally described as Rangea longa Glaessner and Wade, 1966, but the disparate nature of documented specimens has hindered their inclusion in global syntheses and has resulted in these fossils being assigned to at least five different genera in two different clades since their discovery. Detailed study of the type
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Not the first leech: An unusual worm from the early Silurian of Wisconsin J. Paleontol (IF 1.4) Pub Date : 2023-09-04 Simon J. Braddy, Kenneth C. Gass, Michael Tessler
An unusual worm, previously interpreted as the earliest leech, is described from the early Silurian (Llandovery, Telychian) Brandon Bridge Formation Lagerstätte (Waukesha Biota) of Wisconsin (~437 Ma). Lacking preserved internal organs, it is up to ~16 cm long, 8.2 mm wide, with ~250 annulations and a circular structure at one end, interpreted here as the broken end of a molt. It is therefore referred
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Middle Visean (Mississippian) conodonts from shallow-water deposits in the Yashui section, Guizhou, South China, and their stratigraphic significance J. Paleontol (IF 1.4) Pub Date : 2023-08-31 Qiulai Wang, Yuping Qi, Le Yao
The typical Mississippian shallow-water deposits of the Jiusi and Shangsi formations are well exposed in the Yashui section in southern Guizhou, South China. The strata are composed mainly of platform limestones intercalated with shales and sandstones. Conodonts obtained from the limestones are dominated by two assemblages of cavusgnathids: the Cavusgnathus aff. Cav. unicornis and Clydagnathus windsorensis
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Catalogue of fossil genera of Mactridae (Mollusca: Bivalvia) J. Paleontol (IF 1.4) Pub Date : 2023-07-31 Javier H. Signorelli
All genera based on fossil type species belonging to the family Mactridae are alphabetically listed in this work. The oldest records of the Mactridae come from Cretaceous deposits of North America. However, this group of bivalves has been worldwide recorded from the Paleogene and Neogene. An emended diagnosis for each genus is herein provided. In addition to that, type species, type localities, and
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Examining the ontogeny of the Pennsylvanian cladid crinoid Erisocrinus typus Meek and Worthen, 1865 J. Paleontol (IF 1.4) Pub Date : 2023-07-13 Noel J. Hernandez Gomez, Lisette E. Melendez, Whitney A. Lapic, Sarah L. Sheffield, Ronald D. Lewis
Crinoids were major constituents of late Carboniferous (Pennsylvanian) marine ecosystems, but their rapid disarticulation rates after death result in few well-preserved specimens, limiting the study of their growth. This is amplified for cladids, who had among the highest disarticulation rates of all Paleozoic crinoids due to the relatively loose suturing of the calyx plates. However, Erisocrinus typus
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A new Cambrian (Jiangshanian, Sunwaptan) trilobite fauna from Oklahoma and its biostratigraphic significance. J. Paleontol (IF 1.4) Pub Date : 2023-07-13 Sean R. Blackwell, Stephen R. Westrop
The Cambrian (Jiangshanian, Sunwaptan) Honey Creek Formation in the Wichita Mountains region of Oklahoma yielded a new fauna dominated by Monocheilus Resser, 1937 (senior synonym of Stigmacephalus Resser, 1937) in association with Ptychaspis Hall, 1863. It occupies the same stratigraphic position as similar faunas in the Upper Mississippi Valley and Alberta, lying a little above an interval characterized
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Crocodylian princess in Taiwan: Revising the taxonomic status of Tomistoma taiwanicus from the Pleistocene of Taiwan and its paleobiogeographic implications J. Paleontol (IF 1.4) Pub Date : 2023-06-29 Yi-Yang Cho, Cheng-Hsiu Tsai
Toyotamaphimeia is an extinct crocodylian lineage whose name is derived from a mythological Japanese princess. Here, we re-examine the type specimens of a long-forgotten species: Tomistoma taiwanicus from the Pleistocene of Tainan (Taiwan) and revise its taxonomic status to Toyotamaphimeia taiwanicus n. comb., leading to the first recognized species of Toyotamaphimeia outside Japan. Our phylogenetic
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Revision of Jurassic Protobranch Bivalves from Gebel Maghara, northern Sinai, Egypt J. Paleontol (IF 1.4) Pub Date : 2023-06-27 Wagih S. Ayoub-Hannaa, Franz T. Fürsich, Ahmed A. Abdelhady
The Jurassic rocks of Gebel Maghara, northern Sinai, Egypt, contain a well-preserved and highly diverse macrobenthic fauna, dominated by bivalves. This fauna, particularly bivalves and gastropods, have received little attention in the last 100 years. In an attempt to provide a sound database on the marine bivalve diversity of Egypt during the Jurassic period, a first faunal group, the protobranch bivalves
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Late Cambrian Pywackia is a cnidarian, not a bryozoan: Insights from skeletal microstructure J. Paleontol (IF 1.4) Pub Date : 2023-06-22 Steven J. Hageman, Olev Vinn
The phylum Bryozoa had long been the only major phylum unknown from the Cambrian and by inference the Cambrian Explosion of biodiversity. When described in 2010 as a late Cambrian cryptostome bryozoan, Pywackia baileyi Landing in Landing et al., 2010 became the oldest known bryozoan (early Cambrian bryozoans have since been described). Controversy remains about the phylum-level identification of Pywackia
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Pliocene fossils support a New Zealand origin for the smallest extant penguins J. Paleontol (IF 1.4) Pub Date : 2023-06-21 Daniel B. Thomas, Alan J.D. Tennyson, Felix G. Marx, Daniel T. Ksepka
A late Pliocene (3.36–3.06 Ma) exposure of the Tangahoe Formation on the North Island of New Zealand preserves close fossil relatives of many extant seabird clades. Here, we report an extinct member of the little penguin (Eudyptula Bonaparte, 1856) lineage from the Tangahoe Formation—the smallest extinct crown penguin yet known. Eudyptula wilsonae n. sp. is based on the nearly complete skulls of an
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Trilobites from the Cedaria prolifica Zone (Cambrian, upper Guzhangian) of the Precordillera of Mendoza, western Argentina J. Paleontol (IF 1.4) Pub Date : 2023-06-20 M. Franco Tortello
Trilobites from the upper Guzhangian of the southern Argentine Precordillera, preliminarily described by Carlos Rusconi in the 1950s, are revised herein. The specimens studied were collected from an allochthonous limestone block of La Cruz Olistoliths at 200 m northwest of Estancia San Isidro locality (San Isidro area, Mendoza). Taxa comprise Kormagnostus seclusus (Walcott, 1884), Cedaria prolifica
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Morphology, variation, and systematics of the late Cambrian Laurentian dikelocephalid trilobite Walcottaspis vanhornei (Walcott, 1914) J. Paleontol (IF 1.4) Pub Date : 2023-06-13 Shravya Srivastava, Nigel C. Hughes
Walcottaspis vanhornei (Walcott, 1914) is a large, late Cambrian trilobite with a unique pygidial morphology known only from a narrow outcrop belt of the St. Lawrence Formation in the Upper Mississippi Valley. Found in carbonate-rich layers within heterolithic facies that represent the toesets of a prograding shoreface, it is restricted to a single or small number of parasequences. Only four specimens
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New specimens of Cyclocystoides scammaphoris (Echinodermata) from the Upper Ordovician rocks of the American midcontinent with implications for cyclocystoid functional morphology J. Paleontol (IF 1.4) Pub Date : 2023-06-13 Dennis R. Kolata, Terry Frank, Asa Kaplan, Thomas E. Guensburg
New specimens of Cyclocystoides scammaphoris Smith and Paul, 1982, are here reported from the Upper Ordovician Platteville Formation of northern Illinois, Plattin and Decorah groups of east-central Missouri, and Lebanon Limestone of central Tennessee. These fossils reveal skeletal details that provide insight into the anatomy of cyclocystoids. Of particular significance is a network of channels that
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New trilobite assemblage from the lower Cambrian (upper Stage 4) of the Lake Zone, western Mongolia J. Paleontol (IF 1.4) Pub Date : 2023-06-07 Zhixin Sun, Aihua Yang, Fangchen Zhao, Andrey Yu. Zhuravlev, Bing Pan, Chunlin Hu, Qian Feng, Xi Chen, Maoyan Zhu
The western Mongolian Lake Zone was a Neoproterozoic to early Paleozoic volcanic arc where tuffs, lavas, fossiliferous siliciclastics, and carbonates accumulated during the early Cambrian. An uppermost Cambrian Series 2 (upper Stage 4) trilobite assemblage is described here from the Burgasutay Formation representing a continuous lower Cambrian succession at the Seer Ridge of the Great Lake Depression
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Anatomy of the holotype of ‘Probelesodon’ kitchingi revisited, a chiniquodontid cynodont (Synapsida, Probainognathia) from the early Late Triassic of southern Brazil J. Paleontol (IF 1.4) Pub Date : 2023-06-01 Carolina A. Hoffmann, Marco B. de Andrade, Agustín G. Martinelli
Chiniquodontidae is a family of nonmammaliaform probainognathian cynodonts with occurrences in the Middle to Late Triassic of Africa and South America (Brazil and Argentina). The history of the family is marked by changes in composition and revisions due to the poor preservation of the first discovered specimens. Currently, Chiniquodontidae includes two genera and six species. Here, we apply the computed
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New soft-bodied panarthropods from diverse Spence Shale (Cambrian; Miaolingian; Wuliuan) depositional environments J. Paleontol (IF 1.4) Pub Date : 2023-05-31 Julien Kimmig, Stephen Pates, Rhiannon J. LaVine, L.J. Krumenacker, Anna F. Whitaker, Luke C. Strotz, Paul G. Jamison, Val G. Gunther, Glade Gunther, Matt Witte, Allison C. Daley, Bruce S. Lieberman
The Cambrian (Miaolingian; Wuliuan) Spence Shale Lagerstätte of northern Utah and southern Idaho is one of the most diverse Burgess Shale-type deposits of Laurentia. It yields a diverse fauna consisting of abundant biomineralized and locally abundant soft-bodied fossils, along a range of environments from shallow-water carbonates to deep-shelf dark shales. Panarthropods are the dominant component throughout
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Variation in eye lenses of two new Late Devonian phacopid trilobites from western Junggar, NW China J. Paleontol (IF 1.4) Pub Date : 2023-05-29 Rui-Wen Zong
The suborder Phacopina, characterized by schizochroal eyes, is among the most common groups of trilobites in Devonian strata. The marine sediments of the Famennian in western Junggar, Xinjiang, contain abundant low-disparity phacopids, which have previously been designated to Omegops accipitrinus mobilis, Phacops circumspectans tuberculosus, and Omegops cornelius on the basis of small numbers of poorly
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The unusual atrypide brachiopod Qilianotryma suspectum (Popov, 1982) from the Upper Ordovician of the South China paleoplate J. Paleontol (IF 1.4) Pub Date : 2023-05-17 Yuchen Zhang, Colin D. Sproat, Renbin Zhan
The atrypide brachiopod Qilianotryma Xu in Jin et al., 1979 is an early member of the subfamily Spirigerininae initially described from the Katian (Upper Ordovician) Koumenzi Formation of the Qilian Mountains, Qaidam terrane, Northwest China. Qilianotryma suspectum (Popov in Nikiforova et al., 1982) is described for the first time from the Upper Ordovician of South China paleoplate. Serial sectioning
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Pleurocystites? scylla, a new species of pleurocystitid rhombiferan, and comments on early echinoderm teratologies J. Paleontol (IF 1.4) Pub Date : 2023-05-16 Aidan Sweeney, Colin D. Sumrall
Pleurocystitid echinoderms are known to have consistent plating in the theca or body. However, many specimens with aberrant plating are known among glyptocystitoids (Glyptocystella, Hadrocystis, Tyrridiocystis, and so on) as well as the new Ordovician species Pleurocystites? scylla, described here from the Benbolt Formation near Thorn Hill, Tennessee, USA. The presence of an extra plate in the holotype
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Shell and associated operculum in Teiichispira (Macluritidae: Gastropoda) from the Early/Middle Ordovician of the Argentine Precordillera J. Paleontol (IF 1.4) Pub Date : 2023-05-15 Verónica Bertero, Mariel Ferrari, Marcelo G. Carrera
Two species of Teiichispira Yochelson and Jones reported from the Early/Middle Ordovician marine deposits of the San Juan Formation in the Argentine Precordillera are described. The new species Teiichispira teresae n. sp. is a component of the Early/Middle Ordovician marine gastropod assemblage in the studied region; Teiichispira argentina (Kayser), previously known from the San Juan Formation, is
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The first documentation of an Ordovician eurypterid (Chelicerata) from China J. Paleontol (IF 1.4) Pub Date : 2023-05-10 Han Wang, Simon J. Braddy, Joseph Botting, Yuandong Zhang
An early form of eurypterids (Chelicerata), Archopterus anjiensis n. gen. n. sp., is described from the uppermost Ordovician Wenchang Formation of Anji County, Zhejiang Province, South China. It is the earliest record of eurypterids in China and likely the oldest representative of the Adelophthalmidae. The species, represented by a single specimen, is diagnosed by a ventrally preserved prosoma with
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Paleobiological implications of the bone histology of the extinct Australian marsupial Nimbadon lavarackorum J. Paleontol (IF 1.4) Pub Date : 2023-05-05 Anusuya Chinsamy, Karen H. Black, Suzanne J. Hand, Michael Archer
Despite the recognition that bone histology provides much information about the life history and biology of extinct animals, osteohistology of extinct marsupials is sorely lacking. We studied the bone histology of the ca. 15-million-year-old Nimbadon lavarackorum from Australia to obtain insight into its biology. The histology of thin sections of five femora and five tibiae of juveniles, subadult,
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Crinoids from the Wooster Shale Member of the Cuyahoga Formation, Carboniferous (Mississippian, Tournaisian) of northeastern Ohio J. Paleontol (IF 1.4) Pub Date : 2023-05-04 William I. Ausich, Mark A. Wilson
Nine crinoids are described from the Wooster Shale Member of the Cuyahoga Formation from Wayne and Ashland counties, Ohio, USA. Identifiable elements of the fauna include five camerate crinoids, one flexible crinoid, and three other eucladid crinoids. Five new species are described, including Cactocrinus woosterensis n. sp., Cusacrinus brushi n. sp., Agaricocrinus murphyi n. sp., Decadocrinus laevis
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Conulariid soft parts replicated in silica from the Scotch Grove Formation (lower Middle Silurian) of east-central Iowa J. Paleontol (IF 1.4) Pub Date : 2023-04-27 Heyo Van Iten, Nigel C. Hughes, Douglas L. John, Robert R. Gaines, Matthew W. Colbert
Two specimens of Metaconularia manni (Roy, 1935) from the lower Middle Silurian Scotch Grove Formation (eastern Iowa) exhibit well-defined, relict soft parts replicated in silica. One of these specimens bears phosphatic periderm, whereas the other specimen is a mold. Present within the erect, undistorted apical region of the specimen preserving periderm, on opposite sides of the peridermal cavity,
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Two Asian cricetodontine-like muroid rodents from the Neogene of western North America J. Paleontol (IF 1.4) Pub Date : 2023-04-13 Robert A. Martin, Thomas S. Kelly, Patricia Holroyd
We appraise the morphology and potential origin of two Neogene cricetodontine-like muroids, Pliotomodon primitivus from Late Miocene sediments in northern California and an undescribed muroid from the late Oligocene or Early Miocene of central Oregon. Superficial resemblance of the dentition of Pliotomodon with members of the North American galushamyinan neotominins is considered a result of parallel
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What's behind a name: The taxonomic status of Helicancylus Gabb, 1869 and Hamiticeras Anderson, 1938 (Ammonoidea, Lower Cretaceous) J. Paleontol (IF 1.4) Pub Date : 2023-04-12 Camille Frau, Luc G. Bulot
The present contribution illustrates the type material of the Lower Cretaceous ammonoids Ptychoceras aequicostatus Gabb, 1864 (type species of Helicancylus Gabb, 1869) and Hamiticeras pilsbryi Anderson, 1938 (type species of Hamiticeras Anderson, 1938). The typification and taxonomic validity of both genera are clarified, and the affinities with coeval Acrioceratidae are discussed. Their stratigraphic
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Ancient Basidiomycota in an extinct conifer-like tree, Xenoxylon utahense, and a brief survey of fungi in the Upper Jurassic Morrison Formation, USA J. Paleontol (IF 1.4) Pub Date : 2023-04-11 Aowei Xie, Carole T. Gee, Ning Tian
Although the well-known Upper Jurassic Morrison Formation has yielded abundant fossil plants for nearly a century, relatively little is known about fossil fungi and their ecological relationships to the Morrison flora. The first mention of fungal decay in fossil wood was briefly made over three decades ago, and since then, a few more reports of fungal decay associated with Morrison plants have been
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New paddlefishes (Acipenseriformes, Polyodontidae) from the Late Cretaceous Tanis Site of the Hell Creek Formation in North Dakota, USA J. Paleontol (IF 1.4) Pub Date : 2023-04-11 Eric J. Hilton, Melanie A.D. During, Lance Grande, Per E. Ahlberg
The recently discovered mass mortality of fishes from the Tanis Site in the North Dakota portion of the Late Cretaceous Hell Creek Formation contains many well-preserved, three-dimensional skeletons. Among these are representatives of two acipenseriform families, Acipenseridae (sturgeons) and Polyodontidae (paddlefishes). This paper describes two new monotypic polyodontid genera, expanding our knowledge
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Micro-CT analysis of Katian radiolarians from the Malongulli Formation, New South Wales, Australia, and implications for skeletogenesis J. Paleontol (IF 1.4) Pub Date : 2023-04-05 Siyumini Perera, Jonathan C. Aitchison
A diverse and well-preserved radiolarian assemblage from the Malongulli Formation, New South Wales, Australia, contains 13 species representing 10 genera and six families. One new genus, Wiradjuri, is introduced to accommodate pre-Devonian single-shelled entactiniid taxa, and one new species, Secuicollacta malongulliensis, is recorded together with some previously described forms. The microstructures
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Crinoid calyx origin from stem radial echinoderms J. Paleontol (IF 1.4) Pub Date : 2023-03-29 Thomas E. Guensburg, Rich Mooi, Nicolás Mongiardino Koch
Evidence from the earliest-known crinoids (Tremadocian, Early Ordovician), called protocrinoids, is used to hypothesize initial steps by which elements of the calyx evolved. Protocrinoid calyces are composed of extraxial primary and surrounding secondary plates (both of which have epispires along their sutures) that are unlike those of more crownward fossil and extant crinoids in which equivalent calycinal