Ptychites is among the most widely distributed ammonoid genera of the Triassic and is namesake of a family and superfamily. However, representatives of the genus mostly show low-level phenotypic disparity. Furthermore, a large number of taxa are based on only a few poorly preserved specimens, creating challenges to determine ptychitid taxonomy. Consequently, a novel approach is needed to improve ptychitid diversity studies. Here, we investigate Ptychites spp. from the middle and late Anisian of Nevada. The species recorded include Ptychites embreei n. sp., which is distinguished by an average conch diameter that is much smaller and shows a more evolute coiling than most of its relatives. The new species ranges from the Gymnotoceras mimetus to the Gymnotoceras rotelliformis zones, which makes it the longest-ranging species of the genus. For the first time, the ontogenetic development of Ptychites was obtained from cross sections where possible. Cross-sectioning highlights unique ontogenetic trajectories in ptychitids. This demonstrates that, despite showing little phenotypic disparity, Ptychites was highly ontogenetically differentiated, and thus the high taxonomic diversity at the species level is justified for the species investigated.

UUID: http://zoobank.org/5abe2487-8a00-4b48-adc7-ec7db7a097f7

In recent years the plethora of ‘weird wonders,’ the vernacular for the apparently extinct major body plans documented in many of the Cambrian Lagerstätten, has been dramatically trimmed. This is because various taxa have been either assigned to known phyla or accommodated in larger monophyletic assemblages. Nevertheless, a number of Cambrian taxa retain their enigmatic status. To this intriguing roster we add Dakorhachis thambus n. gen. n. sp. from the Miaolingian (Guzhangian) Weeks Formation Konservat-Lagerstätte of Utah. Specimens consist of an elongate body that lacks appendages but is apparently segmented. A prominent feeding apparatus consists of a circlet of triangular teeth, while posteriorly there are three distinct skeletal components. D. thambus is interpreted as an ambush predator and may have been partially infaunal. The wider affinities of this new taxon remain conjectural, but it is suggested that it may represent a stem-group member of the Gnathifera, today represented by the gnathostomulids, micrognathozoans, and rotifers and possibly with links to the chaetognaths.

UUID: http://zoobank.org/22113e6b-f79e-4d06-9483-144618a61327

A small (1.2 m) columnar carbonate mound in shaley strata equivalent to the Hartselle Sandstone (lower Serpukhovian) near Woodville, northeastern Alabama, was built by a consortium of species unlike those of other Carboniferous mounds in the southeastern United States. The mound contains a new problematic microencruster, Aphralysia anfracta new species, along with encrusting bryozoans (Fistulipora M'Coy, 1849), nonskeletal microbes, and other microencrusters, including Aphralysia capriorae Mamet and Roux, 1975, in a carbonate mud matrix. Mound cavities are filled with three generations of carbonate and siliciclastic sediment. Other biotic constituents of the mound include oncoids, sponges (including Pileospongia Rigby, Keyes, and Horowitz, 1979), gastropods, crinoids, a tabulate coral, and coenobionts, including coccoid calcimicrobes. The mound biota, especially the microencrusters, is dramatically different from those of other Serpukhovian mounds that have been described from Alabama (made by various consortia of rugose corals, fenestrate bryozoans, crinoids, sponges, and nonskeletal microbes). Indeed, the Woodville mound extends the range of the lower Carboniferous encruster Aphralysia Garwood, 1914 to North America.

UUID: http://zoobank.org/d3988875-a7fb-4382-bd14-b17c083d87ad

A new species of microconchid tubeworm, Microconchus cravenensis is described from the Mississippian Cracoean reefs of North Yorkshire, United Kingdom. Despite the fact that some other microconchid species could have attained large tube length, the new species possesses the largest recorded diameter (to 7.7 mm) of the planispirally-coiled (attachment) tube and the largest recorded aperture diameter (8.3 mm) in the helically uncoiled portion. Thus, with respect to these features, Microconchus cravenensis n. sp. is the largest and most robust microconchid species recognized so far. At present, it is only known from the Craven Reef Belt of North Yorkshire, where it attached to corals and possibly bivalve shells, and was preyed upon by small durophagous animals, as indicated by repaired injuries preserved on one of the tubes.

UUID: http://zoobank.org/2ba8f87b-ec1c-4bb3-8615-115e7a527376

A series of well-preserved specimens of the little-known Palaeogene species Biselenaria placentula (Reuss, 1867) warrant the designation of a new family of free-living cheilostome bryozoans, Biselenariidae n. fam. In contrast to the structural organization of all other free-living, lunulitiform cheilostomes, all zooids are enclosed almost completely by cuticular, exterior walls. Yet, like other lunulitiforms, the colony must be regarded as a highly integrated functional unit, as revealed through the unique, highly complex interior architecture. In creating the new monotypic family, the type species Biselenaria placentula is described in detail, while the ambiguous taxonomic status of the only other taxon, B. offa Gregory, 1893, is discussed.

UUID: http://zoobank.org/6ad8a795-c45e-4619-b2bb-46916585fbd9

Octapyrgites elongatus n. gen. n. sp., a relatively rare, tetraradial olivooid (Cnidaria, Medusozoa), is described from Bed 5 of the Yanjiahe Formation (Cambrian Stage 2) near Yichang, China. Although similar to Olivooides and Quadrapyrgites from the Fortunian Stage in consisting of a partially corrugated (longitudinal) periderm with a quadrate (transverse) apical portion and V-shaped apertural lobes, O. elongatus is substantially larger than other olivooids. The elongate apical region of O. elongatus is similar to four-sided Anaconularia anomala (Barrande, 1867), though with a flat tip that may have been an adaption for a sessile mode of life. As in other olivooids, embryonic development in O. elongatus may have been direct. Last, the paucity of olivooids and the absence of pentaradial cnidarians and carinachitids in Cambrian Stage 2 indicate a marked decline in the disparity of cnidarians near the Fortunian–Cambrian Age 2 boundary, when by contrast bilaterians underwent rapid diversification.

UUID: http://zoobank.org/60acc2f9-44f8-4a97-9449-960ad76f8fff

The brachiopods collected from the Kuanyinchiao Beds (Hirnantian, uppermost Ordovician) in Meitan and Zunyi counties, northern Guizhou, include 13 species and one undetermined taxon, dominated by Hirnantia sagittifera (M'Coy, 1851) (which accounts for over one-third of the specimens), together with common Eostropheodonta hirnantensis (M'Coy, 1851). They are assigned to the Hirnantia–Eostropheodonta Community, which probably inhabited a shallow-water, nearshore Benthic Assemblage (BA) 2 to upper BA 3 environment. Population analysis shows that the community was well adapted to this environment after the first phase of the end-Ordovician mass extinction. Representative specimens of all the species are illustrated, and a new species, Minutomena missa, is described herein. The variation in Hirnantia sagittifera was noted in many of previous studies but was not statistically evidenced. Here we have measured representative specimens of that famous species from the major paleoplates and terranes in the world, along with other species assigned to the genus from South China. Having used principal component analysis (PCA), significant variations in the species are documented statistically and revised, and three nominal species, one subspecies, and two morphotypes are now reassigned to Hirnantia sagittifera sensu stricto.

UUID: http://zoobank.org/references/3f83fb1e-a6dd-4585-9f9f-9586dad28244

A Late Ordovician brachiopod fauna from the Black River quadrangle (D-1 1:63,360 scale) of east-central Alaska comprises taxa typical of the Late Ordovician brachiopod fauna in the pericratonic epeiric seas of Laurentia, including Hesperorthis pyramidalis (Twenhofel, 1928), Plaesiomys occidentalis (Okulitch, 1943), Eoplectodonta sp., Holtehdalina sp., Leptaena sp., Brevilamnulella minuta n. sp., Tcherskidium tenuicostatum n. sp., Rhynchotrema iowense Wang, 1949, and Whitfieldella sp. The presence of Plaesiomys occidentalis and Tcherskidium tenuicostata n. sp. indicates a latest Katian age by correlation with similar species in the Mackenzie Mountains, southern Manitoba, Anticosti Island, the American midcontinent, Kolyma, and Siberia. Cluster analysis based on 20 well-studied late Katian brachiopod faunas from various regions within Laurentia and elsewhere in other tectonic plates suggests that the small brachiopod faunule from Alaska has the strongest paleobiogeographic affinity with Laurentia, confirming that the Black River quadrangle of Alaska was part of Laurentia during the Late Ordovician.

UUID: http://zoobank.org/6b387856-61d5-4685-a592-faf5287c1e0f

Five genera of anthaspidellid and streptosollenid demosponges are described from the Ordovician Lenoir Limestone near Lenoir City, Loudon County, Tennessee, USA including: Rhopalocoelia regularis Raymond and Okulitch, Rugocoelia loudonensis n. sp., Psarodictyum sp. (Anthaspidellidae), Allosacus pedunculatus n. sp., and Zitelella varians Raymond and Okulitch (Streptosolenidae). These findings confirm the major paleobiogeographic picture for Laurentian sponges (i.e., the differential distribution of sponge faunas along both North American margins), because none of these eastern margin species has been reported from western margin faunas. Only one genus typical of the Great Basin fauna, Rugocoelia Johns, 1994, is reported from Tennessee, but as a new species. Possible explanations are discussed for this differential distribution, mainly related to climatic constraints or sedimentary differences, preventing the free distribution of sponge species between Laurentian continental margins.

UUID: http://zoobank.org/2b990a4c-7bc8-4eb6-b8a9-fe4ecf7bdbf9

In the 1950s, Carlos Rusconi reported the biostratigraphically important Furongian trilobites Elvinia Walcott and Irvingella Ulrich and Resser from an exotic limestone block (La Cruz Olistolith) of the San Isidro area, Precordillera of Mendoza, western Argentina. Although several local species were erected by Rusconi at that time, most of them were later listed as junior synonyms of E. roemeri (Shumard) or I. major Ulrich and Resser, and this was followed in subsequent studies. A systematic revision of all the available specimens of Elvinia and Irvingella from the Rusconi collection at the Museo de Ciencias Naturales y Antropológicas J.C. Moyano (Mendoza) is provided herein. The occurrence of E. roemeri is supported by the present study, while the associated Irvingella species include I. jorusconii Rusconi, I. platycephala Rusconi, and Irvingella sp. The latter represent “advanced” forms in terms of morphological development in the Irvingella lineage, and these, together with E. roemeri, are typical of the uppermost part of the Elvinia Zone (uppermost Steptoean). Irvingella jorusconii, I. platycephala, and Irvingella sp. appear to be endemic to the Argentinian Precordillera, but are related to species from central Texas and northwest Canada.

Phragmolites lissoni new species is described from 11 specimens found in the Sandbian Calapuja Formation near Calapuja in Peru. The deposits are part of the Central Andean Basin. This is the hitherto only systematically described Ordovician gastropod from Peru. The species is from a brachiopod-dominated siliciclastic sequence and is associated with bryozoans. Most specimens are preserved as external molds, but latex casts yield excellent details of shell ornamentation and are used as a basis for evaluating this feature in the genus. The characteristic ornamentation of Phragmolites should be called corrugated lamellae, and the individual elements on these should be referred to as flutes. A descriptive terminology for these is suggested. The development and shape of the corrugated lamellae and flutes could be biomechanical process. A second component in lamellar formation is the alternation between regular incremental growth and formation of a lamella. Phragmolites is mainly found in shallow-water carbonate facies from tropical latitudes in the Sandbian and a mid-latitude presence in Peru is unexpected. Brachiopods from the same section in Calapuja show affinities with faunas of the Mediterranean margin of Gondwana but also weak links with Avalonia. Phragmolites is found abundantly in deeper-water facies in Laurentia, and a broad tolerance to facies and temperature and possible planktotrophy might have allowed a wide geographical dispersal of the genus. The scant record of Ordovician gastropods in the Central Andean Basin precludes comparison with the disparate record of the Ordovician gastropod taxa from the Precordillera, which do not include Phragmolites.

UUID: http://zoobank.org/References/fbd7a43e-a610-42fd-a31d-b1a16fa69c9b

The Ao Mo Lae Formation of the Tarutao Group crops out on Thailand's Tarutao Island and contains a diverse assemblage of late Furongian trilobite taxa, including several endemic forms. This study presents a new genus and species, Satunarcus molaensis, discovered at two locations on the island. A cladistic analysis of the kaolishaniid subfamily Mansuyiinae in light of Satunarcus and similar genera known from across upper Cambrian equatorial Gondwanan rocks suggests that the subfamily is polyphyletic in its current definition, and thus is not a natural group. Separating Mansuyia Sun, 1924 from the other taxa conventionally placed in Mansuyiinae permits recognition of a previously unrecognized monophyletic subfamily Ceronocarinae new subfamily. As established herein, this kaolishaniid subfamily contains Satunarcus n. gen. and all genera previously recognized as Mansuyiinae. with the exception of Mansuyia itself. Ceronocarinae n. subfam. occur in middle Jiangshanian to middle Cambrian Stage 10 sedimentary rocks from Australia, South China, North China, and Sibumasu, with most genera endemic to Australia.

UUID: http://zoobank.org/618c5136-73f0-4912-a7d3-e56559d2a76c

A well-preserved fauna of largely articulated trilobites is described from three new localities close to one another in the Bull River Valley, southeastern British Columbia. All the trilobites from these localities are from the lower or middle part of the Wujiajiania lyndasmithae Subzone of the Elvinia Zone, lower Jiangshanian, in the McKay Group. Two new species are proposed with types from these localities: Aciculolenus askewi and Cliffia nicoleae. The trilobite (and agnostid) fauna from these localities includes at least 20 species: Aciculolenus askewi n. sp., Agnostotes orientalis (Kobayashi, 1935), Cernuolimbus ludvigseni Chatterton and Gibb, 2016, Cliffia nicoleae n. sp., Elvinia roemeri (Shumard, 1861), Grandagnostus? species 1 of Chatterton and Gibb, 2016, Eugonocare? phillipi Chatterton and Gibb, 2016, Eugonocare? sp. A, Housia vacuna (Walcott, 1912), Irvingella convexa (Kobayashi, 1935), Irvingella flohri Resser, 1942, Irvingella species B Chatterton and Gibb, 2016, Olenaspella chrisnewi Chatterton and Gibb, 2016, Proceratopyge canadensis (Chatterton and Ludvigsen, 1998), Proceratopyge rectispinata (Troedsson, 1937), Pseudagnostus cf. P. josepha (Hall, 1863), Pseudagnostus securiger (Lake, 1906), Pseudeugonocare bispinatum (Kobayashi, 1962), Pterocephalia sp., and Wujiajiania lyndasmithae Chatterton and Gibb, 2016. Pseudagnostus securiger, a widespread early Jiangshanian species, has not been previously recorded from southeastern British Columbia. Non-trilobite fossils collected from these localities include brachiopods, rare trace fossils, a complete silica sponge (Hyalospongea), and a dendroid graptolite. The faunas from these localities are more diverse and better preserved than those from other previously documented localities of the same age in the region.

Additional specimens of a rare species, found by amateur collectors in previously documented localities of slightly younger age (upper part of Wujiajiania lyndasmithae Subzone) in the same region, are documented. These new specimens, when combined with an earlier discovered specimen, provide adequate type material to propose a new species of Labiostria, L. gibbae, which may be useful for biostratigraphy.

UUID:http://zoobank.org/89551eac-b3af-4b2b-8ef3-7c2e106a560d

An example of parasitic drilling in a rhynchonelliform brachiopod is described from the Shiyanhe Formation (Katian, Upper Ordovician) of Henan, central China. The boring extends into the shell almost perpendicular to the surface. The shell has been serially sectioned, and the trace (including boring and bioclaustration) has been modeled in three dimensions. Healing of the shell evident in serial sections supports a long-term relationship between the brachiopod and borer that we interpret as parasitic. Platyceratid gastropods, found at the same locality as these brachiopods, are the most likely drilling organism. Previous reports of Paleozoic brachiopod parasitic traces can be classified into two main groups, constructive association and destructive association, depending on whether parasites damage brachiopod shells. The example in this study belongs to the second type as the brachiopod shell has been partly damaged by the borer.

Extant medusozoans (phylum Cnidaria) are dominated by forms showing tetraradial symmetry, but stem-group medusozoans of early Cambrian age collectively exhibit tetra-, bi-, penta-, and hexaradial symmetry. Moreover, the developmental and evolutionary relationships between four-fold and other types of radial symmetry in medusozoans remain poorly understood. Here we describe a new hexangulaconulariid, Septuconularia yanjiaheensis new genus new species, from Bed 5 of the Yanjiahe Formation (Cambrian Stage 2) in the Three Gorges area of Hupei Province, China. The laterally compressed, biradially symmetrical periderm of this species possesses 14 gently tapered faces, the most of any hexangulaconulariid described thus far. The faces are bordered by longitudinal ridges and crossed by short, irregularly spaced transverse ribs. Longitudinally, the periderm consists of three regions that probably correspond, respectively, to an embryonic stage, a transient juvenile stage, and a long adult stage. Septuconularia yanjiaheensis may have been derived from six-faced Hexaconularia (Fortunian Stage), which is morphologically intermediate between Septuconularia yanjiaheensis and Arthrochites. Furthermore, conulariids sensu stricto, carinachitids, and hexangulaconulariids may constitute a monophyletic group united by possession of an organic or organophosphatic periderm exhibiting longitudinal (corner) sulci, a facial midline, and offset of transverse ribs along the facial midline.

UUID: http://zoobank.org/01a972aa-aef3-4eef-a9a5-c2d8c3dda615

Assessment of unique and potentially significant fossils may be considerably compromised by surrounding matrix. This paper assesses a fossil barnacle group from the mid to late Eocene of Seymour Island, off the Antarctic Peninsula, that potentially has very significant phylogenetic importance. It discusses why the specimen could be significant, and describes and applies as a proof of concept an advanced imaging technique, using X-ray Computed Tomography (CT), that was effectively employed to confirm systematic taxonomy with virtual 3-D sections through the specimen. In this case, the Antarctic barnacle's complex internal plate morphologies were resolved by advanced 3-D imaging, such that a taxonomic attribution could be made to either the Archaeobalanidae or Austrobalanidae, excluding the initial assessment of Coronulidae, which would have otherwise been allusive.

The dalmanitid trilobite Kasachstania Maksimova, 1972, previously reported from the Lower Devonian of Kazakhstan and North America (USA) and the upper Silurian–Lower Devonian of South America (Bolivia and Argentina), is revised. Kasachstania kasachstanica (Balashova in Maksimova,1968) and K. septicostata (Maksimova, 1968) are regarded as junior synonyms of the type species K. saryarkensis (Maksimova, 1960), all from the Lower Devonian of the type locality in central Kazakhstan (northern Balkhash). On the basis of a new diagnosis, K. ulrichi ulrichi (Delo, 1940) from the Emsian of the United States, K. ulrichi asiatica (Maksimova, 1968), K. pristina (Maksimova, 1968), and K. alperovichi Pour et al., 2019, from the Lower Devonian of Kazakhstan, K. andii (Kozłowski, 1923) from the upper Silurian–Lower Devonian of Bolivia, and K. gerardoi Edgecombe and Ramsköld, 1994, from the upper Silurian–Lower Devonian of Bolivia and Argentina are excluded from Kasachstania. This genus, represented only by K. saryarkensis and K. kiikbaica (Maksimova, 1968), is restricted to the Lower Devonian of central Kazakhstan, corresponding to the Balkhash–Mongolo–Okhotsk province in the paleobiogeographic context of the Old World Realm, instead of being nearly cosmopolitan as previously considered. In addition, we provide some remarks about Saryarkella Maksimova, 1978b, a monospecific dalmanitid genus largely overlooked although valid from the Emsian of the same area in central Kazakhstan.