Saetaspongia sponges from the Cambrian (Stage 4) Balang Formation of Guizhou, China

2021 ◽  
pp. 1-13
Author(s):  
Chenchen Ling ◽  
Jin Peng ◽  
Hui Zhang ◽  
Yifan Wang ◽  
Yunbin Shao ◽  
...  
Keyword(s):  
Phylogenetic Position ◽  
New Taxon ◽  
Crown Group ◽  
Critical Feature ◽  
Additional Specimen ◽  
Fossil Evidence ◽  
New Information ◽  
Class Level ◽  
Stage 4 ◽  
New Material

Abstract Saetaspongia so far cannot be confidently assigned to any class-level crown group. Clarifying its phylogenetic position requires new information provided by more detailed studies of previously described and/or new material. Some sponge fossils with the typical skeletal architecture of Saetaspongia have recently been recognized in the Cambrian (Stage 4) Balang Biota of Guizhou, China, including S. jianhensis new species and S. cf. S. densa. The new taxon is characterized by the following features: spicules are fine monaxons and are inclined to be loosely to densely arranged into plumose arrays; skeleton is composed primarily of one major plumose bundle, with an uncertain number (perhaps two) of small plumose arrays; and primary skeleton is occasionally interspersed with some irregularly oriented individual spicules. An additional specimen consisting of large monaxons, with plumose structures and overlying irregular coarse monaxons, closely fits the description and illustrations of previously described S. cf. S. densa. By combining information from previous studies and the present research, fossil evidence indicates that the plumose architecture is a critical feature diagnostic of Saetaspongia and that there are no hexactine-based spicules in this genus. The new material from the Balang Biota further supports the notion that Saetaspongia has a protomonaxonid rather than a hexactinellid affinity. Fossil evidence suggests that Saetaspongia had a wide biogeographic distribution during the early Cambrian and the stratigraphic distribution of this genus extends up to Stage 4. UUID: http://zoobank.org/e9ca5e4a-134c-4daa-9266-19085e32614f.

An Ordovician Pycnogonid (Sea Spider) with Serially Subdivided ‘Head’ Region

2013 ◽  
Vol 87 (3) ◽  
pp. 395-405 ◽  
Author(s):  
David M. Rudkin ◽  
Michael B. Cuggy ◽  
Graham A. Young ◽  
Deborah P. Thompson
Keyword(s):  
Disjunct Distribution ◽  
Phylogenetic Position ◽  
Complete Fusion ◽  
New Taxon ◽  
Upper Ordovician ◽  
Crown Group ◽  
Head Region ◽  
Group Position ◽  
Late Cambrian ◽  
Sea Spider

The bizarre morphology of living Pycnogonida, known colloquially as sea spiders, has long fueled dissent over their status within the arthropods. Pycnogonids figure prominently in recent analyses of anterior limb homologies and ancestral crown-group euarthropod relationships, with support for the concept of Pycnogonida as sister taxon to Euchelicerata now contested by proponents of a more basal position between Radiodonta and all other arthropods. A challenge to further elucidation of their phylogenetic position is the exceptional rarity and disjunct distribution of pycnogonids in the fossil record, due largely to their fragile unmineralized exoskeletons. New fossil discoveries therefore have the potential to add significantly to knowledge of their evolution, paleoecology, and paleobiogeography. Here we report the first known occurrence of fossil pycnogonids from rocks of Ordovician age, bridging a 65 Myr gap between controversial late Cambrian larval forms and a single documented Silurian specimen. The new taxon,Palaeomarachne granulatan. gen. n. sp., from the Upper Ordovician (ca. 450 Ma) William Lake Konservat-Lagerstätte deposit in Manitoba, Canada, is also the first reported from Laurentia. It is the only record thus far of a fossil sea spider in rocks of demonstrably shallow marine origin. Four incomplete, partially disarticulated molts represent a relatively large, robust animal with a series of five segment-like elements in a ‘head’ region that does not incorporate the first of four preserved limb-bearing trunk segments. This unique pattern may reflect the plesiomorphic condition prior to complete fusion of anterior ‘head’ elements and first trunk segment to form a cephalosoma, as seen in all eupycnogonids.Palaeomarachne granulatais interpreted as occupying a basal stem-group position in the Pycnogonida.

scholarly journals New Material of Paleocene-Eocene Pellornis (Aves: Gruiformes) Clarifies the Pattern and Timing of the Extant Gruiform Radiation

Diversity ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 102 ◽  
Author(s):  
Grace Musser ◽  
Daniel T. Ksepka ◽  
Daniel J. Field
Keyword(s):  
Mass Extinction ◽  
Phylogenetic Analyses ◽  
Divergence Time ◽  
Phylogenetic Position ◽  
Postcranial Skeleton ◽  
Holotype Specimen ◽  
New Information ◽  
Mechanical Preparation ◽  
New Material ◽  
Early Radiation

Pellornis mikkelseni is an early gruiform from the latest Paleocene-earliest Eocene Fur Formation of Denmark. At approximately 54 million years old, it is among the earliest clear records of the Gruiformes. The holotype specimen, and only material thus far recognised, was originally considered to comprise a partial postcranial skeleton. However, additional mechanical preparation of the nodule containing the holotype revealed that the skeleton is nearly complete and includes a well-preserved skull. In addition to extracting new information from the holotype, we identify and describe two additional specimens of P. mikkelseni which reveal further morphological details of the skeleton. Together, these specimens show that P. mikkelseni possessed a schizorhinal skull and shared many features with the well-known Paleogene Messelornithidae (“Messel rails”). To reassess the phylogenetic position of P. mikkelseni, we modified an existing morphological dataset by adding 20 characters, four extant gruiform taxa, six extinct gruiform taxa, and novel scorings based on the holotype and referred specimens. Phylogenetic analyses recover a clade containing P. mikkelseni, Messelornis, Songzia and crown Ralloidea, supporting P. mikkelseni as a crown gruiform. The phylogenetic position of P. mikkelseni illustrates that some recent divergence time analyses have underestimated the age of crown Gruiformes. Our results suggest a Paleocene origin for this important clade, bolstering evidence for a rapid early radiation of Neoaves following the end-Cretaceous mass extinction.

scholarly journals Unexpected larger distribution of paleogene stem-rollers (AVES, CORACII): new evidence from the Eocene of Patagonia, Argentina

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Federico J. Degrange ◽  
Diego Pol ◽  
Pablo Puerta ◽  
Peter Wilf
Keyword(s):  
Hind Limb ◽  
Divergence Time ◽  
First Record ◽  
Morphological Data ◽  
New Taxon ◽  
Early Eocene ◽  
Important Data ◽  
New Material ◽  
Holarctic Region ◽  
New Evidence

AbstractHere we present the first record of a stem-Coracii outside the Holarctic region, found in the early Eocene of Patagonia at the Laguna del Hunco locality. Ueekenkcoracias tambussiae gen. et sp. nov. consists of an incomplete right hind limb that presents the following combination of characters, characteristic of Coracii: relatively short and stout tibiotarsus, poorly developed crista cnemialis cranialis, short and wide tarsometatarsus, with the tuberositas m. tibialis cranialis located medially on the shaft, and curved and stout ungual phalanges. Although the presence of a rounded and conspicuous foramen vasculare distale and the trochlea metatarsi II strongly deflected medially resemble Primobucconidae, a fossil group only found in the Eocene of Europe and North America, our phylogenetic analysis indicates the new taxon is the basalmost known Coracii. The unexpected presence of a stem-Coracii in the Eocene of South America indicates that this clade had a more widespread distribution than previously hypothesized, already extending into the Southern Hemisphere by the early Eocene. Ueekenkcoracias tambussiae represents new evidence of the increasing diversity of stem lineages of birds in the Eocene. The new material provides novel morphological data for understanding the evolutionary origin and radiation of rollers and important data for estimates of the divergence time of the group.

A giant within Carpocorini (Hemiptera: Heteroptera: Pentatomidae): Description of Adustonotus graziae sp. nov.

Zootaxa ◽  
2021 ◽  
Vol 4958 (1) ◽  
pp. 489-502
Author(s):  
FILIPE MICHELS BIANCHI
Keyword(s):  
Morphological Characters ◽  
The Other ◽  
Total Evidence ◽  
Valid Species ◽  
Phylogenetic Position ◽  
New Taxon ◽  
Large Size ◽  
Internal Genitalia ◽  
Evidence Analysis ◽  
Heteroptera Pentatomidae

The Carpocorini are distributed worldwide, and it is one of the most speciose tribes within the Pentatomidae with 127 genera and more than 500 valid species. Recently, Adustonotus Bianchi was described to contain eight species formerly placed within Euschistus Dallas. Among them, Adustonotus grandis (Rolston) and Adustonotus latus (Dallas) are remarkable for their large size. Herein, the phylogenetic position of a new taxon is inferred by a total evidence analysis based on 85 morphological characters and four molecular markers. Adustonotus graziae sp. nov. is described, and is recovered in a polytomic lineage, including A. grandis and A. latus. These species share a solid combination of features that enable them to be separated from the other Adustonotus species (e.g., large size, the humeral angles spatulate and exceptionally produced, and the capsula seminalis shortened). Illustrations of external and internal genitalia, and a distributional map are provided. 

scholarly journals New or previously unrecorded avian taxa from the Middle Eocene of Messel (Hessen, Germany)

Fossil Record ◽  
2000 ◽  
Vol 3 (1) ◽  
pp. 207-219 ◽  
Author(s):  
G. Mayr
Keyword(s):  
Middle Eocene ◽  
The Other ◽  
New Taxon ◽  
New Information ◽  
Wenn Sich

Three new or from this site previously unrecorded birds are described from the Middle Eocene of Messel (Hessen, Germany). <i>Serudaptus pohli</i> n. gen. n. sp. is a new taxon of the Pseudasturidae and is distinguished from the other species of this family by its short and stout tarsometatarsus and the long and strong claws. An isolated foot of a gruiform bird is assigned to <i>Idiornis</i> cf. <i>itardiensis</i> (Idiornithidae) and would, if this assignment can be confirmed, demonstrate the existence of this species for a period of 23 million years. The proportions of the toes suggest that <i>Idiornis</i> cf. <i>itardiensis</i> was less cursorial than its next recent relatives, the Cariamidae. In addition thereto, an exceptionally well preserved skeleton of a sandcoleid bird (Coliiformes: Sandcoleidae) gives new information on the osteology and feathering of sandcoleid birds. The specimen resembles the genera <i>Eoglaucidium</i> and <i>Anneavis</i> but it has not been possible to assign it to one of these two genera with certainty. <br><br> Drei neue oder von dieser Fundstelle bisher nicht nachgewiesene Vögel werden aus dem Mittel-Eozän von Messel (Hessen, Deutschland) beschrieben. <i>Serudaptus pohli</i> n. gen. n. sp. ist ein neues Taxon der Pseudasturidae und unterscheidet sich von den anderen Arten dieser Familie durch den kurzen und gedrungenen Tarsometatarsus und die langen, kräftigen Krallen. Der isolierte Fuß eines gruiformen Vogels wird <i>Idiornis</i> cf. <i>itardiensis</i> (Idiornithidae) zugeordnet und würde, wenn sich diese Zuordnung bestätigt, die Existenz dieser Art über einen Zeitraum von 23 Millionen Jahren zeigen. Die Zehenproportionen legen nahe, dass <i>Idiornis</i> cf. <i>itardiensis</i> weniger an eine laufende Lebensweise angepasst war als seine nächsten rezenten Verwandten, die Cariamidae. Darüber hinaus zeigt ein außergewöhnlich gut erhaltenes Skelett eines Vertreters der Sandcoleidae bisher unbekannte Einzelheiten der Osteologie und Befiederung dieser Familie. Das Exemplar ähnelt den Gattungen <i>Eoglaucidium</i> und <i>Anneavis</i>, konnte jedoch keiner der beiden Gattungen mit Sicherheit zugeordnet werden. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.20000030110" target="_blank">10.1002/mmng.20000030110</a>

Ichthyosaurs from the Upper Triassic (Carnian–Norian) of the New Siberian Islands, Russian Arctic, and their implications for the evolution of the ichthyosaurian basicranium and vertebral column

2021 ◽  
pp. 1-24
Author(s):  
Nikolay G. ZVERKOV ◽  
Dmitry V. GRIGORIEV ◽  
Andrzej S. WOLNIEWICZ ◽  
Alexey G. KONSTANTINOV ◽  
Evgeny S. SOBOLEV
Keyword(s):  
Vertebral Column ◽  
Cervical Vertebrae ◽  
Upper Triassic ◽  
Late Triassic ◽  
Phylogenetic Position ◽  
New Taxon ◽  
Russian Arctic ◽  
Micro Computed Tomography ◽  
New Siberian Islands ◽  
Group Relationships

ABSTRACT The first ichthyosaurian specimens discovered from the Upper Triassic of the Russian Arctic (Kotelny Island, New Siberian Islands) are described herein. They include the remains of large- to small-bodied ichthyosaurians originating from six stratigraphic levels spanning the lower Carnian to middle Norian. The material is mostly represented by isolated vertebrae and ribs, which are not possible to accurately diagnose, but also includes specimens comprising associated vertebrae and a fragmentary skeleton that preserves cranial remains (parabasisphenoid, fragmentary quadrate, partial mandible and hyoids). Based on vertebral and rib morphology, we identify the specimens as representatives of the following taxonomic groups: large-bodied shastasaurids, medium-sized indeterminate ichthyosaurians with a single rib facet in the presacral centra, and small euichthyosaurians with double rib facets present throughout the presacral vertebrae that likely represent toretocnemids and/or basal parvipelvians. In addition, the cranial and mandibular remains preserved in one of the specimens, ZIN PH 5/250, were studied using micro-computed tomography. Its mandible is highly similar to that of toretocnemids, whereas the parabasisphenoid demonstrates a peculiar combination of both plesiomorphic and derived character states, providing the first detailed data on this cranial element in a Late Triassic ichthyosaurian. Furthermore, the specimen also demonstrates a distinctive condition of rib articulation in the anteriormost presacral (cervical) vertebrae, which together with other features allows for the erection of a new taxon – Auroroborealia incognita gen. et sp. nov. Although the phylogenetic position of this taxon is uncertain due to its fragmentary nature, its anatomy, indicating toretocnemid or parvipelvian affinities, further supports the previously hypothesised sister-group relationships between these two clades. The morphology of the parabasisphenoid and vertebral column of the new taxon is discussed in broader contexts of the patterns of evolution of these skeletal regions in ichthyosaurs.

New insights into the evolution of lateral compound eyes in Palaeozoic horseshoe crabs

2019 ◽  
Vol 187 (4) ◽  
pp. 1061-1077 ◽  
Author(s):  
Russell D C Bicknell ◽  
Lisa Amati ◽  
Javier Ortega-Hernández
Keyword(s):  
Convincing Evidence ◽  
Limulus Polyphemus ◽  
Phylogenetic Position ◽  
Compound Eyes ◽  
Crown Group ◽  
Widespread Occurrence ◽  
Eye Evolution ◽  
Stem Group ◽  
Lateral Eye ◽  
Horseshoe Crabs

Abstract Vision allows animals to interact with their environment. Aquatic chelicerates dominate the early record of lateral compound eyes among non-biomineralizing crown-group euarthropods. Although the conservative morphology of lateral eyes in Xiphosura is potentially plesiomorphic for Euarthropoda, synziphosurine eye organization has received little attention despite their early diverging phylogenetic position. Here, we re-evaluate the fossil evidence for lateral compound eyes in the synziphosurines Bunodes sp., Cyamocephalus loganensis, Legrandella lombardii, Limuloides limuloides, Pseudoniscus clarkei, Pseudoniscus falcatus and Pseudoniscus roosevelti. We compare these data with lateral eyes in the euchelicerates Houia yueya, Kasibelinurus amicorum and Lunataspis aurora. We find no convincing evidence for lateral eyes in most studied taxa, and Pseudoniscus roosevelti and Legrandella lombardii are the only synziphosurines with this feature. Our findings support two scenarios for euchelicerate lateral eye evolution. The elongate-crescentic lateral eyes of Legrandella lombardii might represent the ancestral organization, as suggested by the phylogenetic position of this taxon in stem-group Euchelicerata. Alternatively, the widespread occurrence of kidney-shaped lateral eyes in stem-group Xiphosura and stem-group Arachnida could represent the plesiomorphic condition; Legrandella lombardii eyes would therefore be derived. Both evolutionary scenarios support the interpretation that kidney-shaped lateral eyes are ancestral for crown-group Euchelicerata and morphologically conserved in extant Limulus polyphemus.

Crete (Prehistoric)

2013 ◽  
Vol 59 ◽  
pp. 56-67
Author(s):  
John Bennet
Keyword(s):  
The Past ◽  
New Information ◽  
Archaeological Work ◽  
New Material ◽  
Individual Contributions ◽  
The University

Publications of fieldwork continue to appear slowly, but the latest volume of ADelt for Crete, covering the years 2001–2004, appeared in print in summer 2012 (ADelt 56–59 [2001–2004] B5). Inevitably, given the years covered, some of the activity summarized in this volume has already been noted in AG and brief notices of some appears in the decadal summary of the activities of all the prehistoric and Classical ephorias (www.yppo.gr/0/anaskafes; AR 58 [2011–2012] 58). Emphasis here is on those activities not already noted in AG or those where significant new information appears in the new volume of ADelt. The second meeting on Archaeological Work on Crete (AWiC2), alluded to last year (AR 58 [2011–2012] 58), has been published and can be read online through the University of Crete's Library (http://elocus.lib.uoc.gr/dlib/d/0/5/metadata-dlib-1368695830-557833-31681.tkl#). A third meeting is scheduled for December 2013 and will hopefully be made accessible with equally commendable promptness. The proceedings of the Tenth International Cretological Congress held in Chania in 2006 (see AR 53 [2006–2007] 96) are still to appear in print, although e-offprints of individual contributions continue to circulate. New material in this year's entry is therefore drawn primarily from ADelt 56–59 (2001–2004) B5 and AWiC2.The past year has seen a number of significant publications on prehistoric Crete, including the proceedings of several conferences. The publication by the BSA of Intermezzo: Intermediacy and Regeneration in Middle Minoan III Palatial Crete (Macdonald and Knappett [2013]), containing papers presented at a workshop held in 2008, complements volumes noted last year (AR 58 [2011–2012] 58) on Late Minoan IB ceramics (Brogan and Hallager [2011]) and on the Prepalatial and Protopalatial periods (Early Minoan to Middle Minoan II) (Schoep et al. [2011]).

A novel late Early Miocene assemblage of terrestrial gastropods from Santa Cruz (Patagonia, Argentina)

2015 ◽  
Vol 89 (5) ◽  
pp. 748-761 ◽  
Author(s):  
Sergio E. Miquel ◽  
Pablo E. Rodriguez
Keyword(s):  
South America ◽  
New Taxa ◽  
Vegetation Cover ◽  
First Record ◽  
Early Miocene ◽  
New Taxon ◽  
Santa Cruz ◽  
Dense Vegetation ◽  
Humid Environment ◽  
New Information

AbstractA remarkable fossil assemblage composed of five gastropod taxa is described from the Early Miocene of Santa Cruz (Patagonia, Argentina) in southernmost South America. The assemblage includes extinct and living genera South America, and on geographic distributions and represent background new information on spatial and across time distributions as well as identification of new taxa. A new taxon,Patagocharopa enigmatican. gen. n. sp., is tentatively assigned to Charopidae.Gastrocopta patagonican. sp. (Vertiginidae) represents the oldest record ofGastrocoptain Argentina and the southernmost record for the Americas.Punctum patagonicumn. sp. (Punctidae) represents the first record ofPunctumfor continental South America, and characterized by a protoconch with traces of axial costulae and a teleoconch with strong radial ribs.Zilchogyra miocenican. sp. is the first Miocene record of the charopid genusZilchogyra. Fragments of a possibleScolodonta(Scolodontidae) are recorded. Overall, the assemblage represents an important and useful paleoenvironmental tool. This fauna suggests that a more temperate and humid environment than today—with a more dense vegetation cover—was prevalent at this site during the Early Miocene.

First plesiosaur remains from the lower Cretaceous of the Neuquén Basin, Argentina

2003 ◽  
Vol 77 (4) ◽  
pp. 784-789 ◽  
Author(s):  
Dario G. Lazo ◽  
Marcela Cichowolski
Keyword(s):  
Lower Cretaceous ◽  
Sister Group ◽  
Monophyletic Group ◽  
Phylogenetic Position ◽  
Crown Group ◽  
Marine Reptiles ◽  
Stem Group ◽  
Neuquen Basin ◽  
Neuquén Basin

Plesiosaurs constitute a monophyletic group whose stratigraphical range is uppermost Triassic to uppermost Cretaceous (Brown, 1981). They were large predatory marine reptiles, highly adapted for submarine locomotion, with powerful paddle-like limbs and heavily reinforced limb girdles (Saint-Seine, 1955; Romer, 1966; Carroll, 1988; Benton, 1990). The Plesiosauria clade belongs to the Sauropterygia, which has recently been hypothesized as the sister-group of the Ichthyosauria. Together with that clade they form the Euryapsida (Caldwell, 1997). The Sauropterygia can be subdivided into relatively plesiomorphic stem-group taxa from the Triassic (Placodonts, Nothosauroids, and Pistosauroids), and the obligatorily marine crown-group Plesiosauria (Rieppel, 1999). Plesiosaurs are traditionally divided into two superfamilies: Plesiosauroidea, with usually small heads and long necks; and Pliosauroidea, with larger heads and shorter necks (Welles, 1943; Persson, 1963; Brown, 1981). Plesiosauroidea contains three families: Plesiosauridae, Cryptoclididae, and Elasmosauridae (Brown, 1981; Brown and Cruickshank, 1994). The validity of the Polycotylidae Cope, 1869, has long been questioned and its phylogenetic position among Plesiosauria debated, as many consider it to be related to the Pliosauridae or to be a sister-group of the Elasmosauridae (Sato and Storrs, 2000; O'Keefe, 2001).

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