scholarly journals Vase-shaped microfossils from the Neoproterozoic Chuar Group, Grand Canyon: A classification guided by modern testate amoebae

2003 ◽  
Vol 77 (3) ◽  
pp. 409-429 ◽  
Author(s):  
Susannah M. Porter ◽  
Ralf Meisterfeld ◽  
Andrew H. Knoll
Keyword(s):  
New Species ◽  
Common Ancestor ◽  
Grand Canyon ◽  
Morphological Diversity ◽  
Testate Amoebae ◽  
Black Shales ◽  
Last Common Ancestor ◽  
New Genera ◽  
Hexagonal Symmetry ◽  
Crown Group

Vase-shaped microfossil (VSM) assemblages from early diagenetic carbonate nodules in >742 ± 6 Ma black shales of the Chuar Group, Grand Canyon, provide evidence for affinities with testate amoebae. Not only are VSMs exceptionally preserved in Chuar rocks, they exhibit a much higher degree of morphological diversity than was previously known. Using the taxonomy of modern testate amoebae as a guide, nine new species and eight new genera of VSMs are described, augmenting the eight species and two genera already recognized. Taxa described here areMelanocyrillium hexodiademaBloeser, 1985,Trigonocyrillium horodyskii(Bloeser, 1985) n. comb.,T. fimbriatum(Bloeser, 1985) n. comb.,Cycliocyrillium simplexn. sp.,C. torquatan. sp.,Bonniea dacrucharesn. sp.,B. pytinaian. sp.,Trachycyrillium pudensn. sp.,Palaeoarcella athanatan. sp.,Hemisphaeriella ornatan. sp.,Bombycion micronn. sp., andMelicerion poikilonn. sp. All of the test characters observed in VSM taxa (e.g., collars; indentations; hexagonal symmetry; lobed, triangular or invaginated apertures; curved necks) occur in modern testate amoeban taxa, though not always in the same combinations. Some VSM species have characters found today in diverse extant taxa, making it difficult to assess their relationships. A few species, however, have character combinations that closely approximate those found in specific genera of both lobose and filose testate amoebae, suggesting that at least stem group, and possibly crown group, representatives of these taxa were present ∼742 Ma.These fossils indicate that ecosystems were diverse and complex, that eukaryotic biomineralization had already evolved, and that the last common ancestor of animals+fungi had already appeared by ∼750 Ma.

scholarly journals The debated question of asymmetrical rhynchonellids (Brachiopoda, Rhynchonellida): examples from the Late Cretaceous of Western Europe

2020 ◽  
Vol 191 ◽  
pp. 1
Author(s):  
Danièle Gaspard ◽  
Sylvain Charbonnier
Keyword(s):  
New Species ◽  
Late Cretaceous ◽  
Western Europe ◽  
Anterior Margin ◽  
Morphological Diversity ◽  
New Genera ◽  
New Material ◽  
A New Species ◽  
Se France ◽  
Sw France

Many Cretaceous asymmetrical rhynchonellid brachiopods (Brachiopoda, Rhynchonellida) have long been considered as Rhynchonella difformis (Valenciennes in Lamarck, 1819). After a revision, Owen (1962) included the Cenomanian specimens from Europe in Cyclothyris M’Coy, 1844. Later, Manceñido et al. (2002) confirmed this decision and critically mentioned the name of another asymmetrical rhynchonellid genus from Spain, Owenirhynchia Calzada in Calzada and Pocovi, 1980. Specimens with an asymmetrical anterior margin (non particularly ecophenotypical), from the Late Coniacian and the Santonian of Les Corbières (Aude, France) and Basse-Provence (SE France) are here compared to specimens of the original Cenomanian species C. difformis. They are also compared to new material from the Northern Castilian Platform (Coniacian-Santonian, N Spain) and to Rhynchonella globata Arnaud, 1877 (Campanian, Les Charentes, Dordogne, SW France) and Rh. vesicularis Coquand, 1860 (Campanian, Charente, SW France). These observations document the great morphological diversity among all these species and lead us to erect a new species: Cyclothyris grimargina nov. sp. from the type material of Arnaud, and two new genera: Contortithyris nov. gen. including Contortithyris thermae nov. sp., Beaussetithyris nov. gen. including Beaussetithyris asymmetrica nov. sp. All of these brachiopods fundamentally present an asymmetrical state which origin is discussed.

scholarly journals An early Cambrian polyp reveals an anemone-like ancestor for medusozoan cnidarians

2021 ◽  
Author(s):  
Yang Zhao ◽  
Luke Parry ◽  
Jakob Vinther ◽  
Frances S. Dunn ◽  
Yujing Li ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Fossil Record ◽  
Soft Tissues ◽  
Common Ancestor ◽  
Last Common Ancestor ◽  
Early Cambrian ◽  
Crown Group ◽  
Sessile Polyp ◽  
Animal Evolution ◽  
Chengjiang Biota

Extant cnidarians are a disparate phylum of non-bilaterians and their diploblastic body plan represents a key step in animal evolution. Anthozoans (anemones, corals) are benthic polyps, while adult medusozoans (jellyfishes) are dominantly pelagic medusae. A sessile polyp is present in both groups and is widely conceived as the ancestral form of their last common ancestor. However, the nature and anatomy of this ancestral polyp, particularly of medusozoans, are controversial, owing to the divergent body plans of both groups in the extant lineages and the rarity of medusozoan soft tissues in the fossil record. Here we redescribe the enigmatic Conicula striata Luo et Hu from the early Cambrian Chengjiang biota, south China, which has previously been interpreted as a polyp, lophophorate or deuterostome. We show that C. striata possessed features of both anthozoans and medusozoans. Its stalked polyp and fully encasing conical, annulated organic skeleton (periderm) are features of medusozoans. However, the gut is partitioned by ~28 mesenteries, and has a tubular pharynx, resembling anthozoans. Our phylogenetic analysis recovers C. striata as a stem medusozoan, indicating that the enormously diverse medusozoans were derived from an anemone-like ancestor, with the pharynx lost and number of mesenteries reduced prior to the origin of crown group Medusozoa.

Systematics of organic-walled microfossils from the ca. 780–740 Ma Chuar Group, Grand Canyon, Arizona

2016 ◽  
Vol 90 (5) ◽  
pp. 815-853 ◽  
Author(s):  
Susannah M. Porter ◽  
Leigh Anne Riedman
Keyword(s):  
New Species ◽  
Grand Canyon ◽  
Time Interval ◽  
New Combinations ◽  
Crown Group ◽  
Widespread Species ◽  
Fine Grained ◽  
Transmitted Light Microscopy ◽  
Three New Species ◽  
First Time

AbstractThe ca. 780–740 Ma Chuar Group, Grand Canyon, Arizona, provides an exceptional record of life during the diversification of crown-group eukaryotes, just prior to the first Cryogenian glaciation. We document in detail the assemblage of organic-walled microfossils preserved in fine-grained siliciclastics throughout the unit. In contrast with earlier studies, we primarily used SEM to document fossil morphologies, augmented by transmitted light microscopy, FIB-SEM, and TEM. This resulted in the discovery of new species and the recognition of broad-ranging, intraspecific biological and taphonomic variation in other species. Twenty-two species and five unnamed morphotypes are described, including three new species:Kaibabia gemmulella,Microlepidopalla mira, andVolleyballia dehlerae; two new combinations:Galerosphaera walcottiiandLanulatisphaera laufeldii; and 17 previously described forms. The possible colonial green algaPalaeastrum dyptocranumButterfield in Butterfield, Knoll, and Swett, 1994 and the index fossilCerebrosphaera globosa(Ogurtsova and Sergeev, 1989) Sergeev and Schopf, 2010 (=C. buickiiButterfield, 1994) are described for the first time from Chuar rocks.Lanulatisphaera laufeldii, a locally abundant and globally widespread species characterized by submicrometer filamentous processes that form a reticulate network, may be a useful marker for the time interval just before the appearance of vase-shaped microfossils (VSMs) ca. 740 Ma.Organic-walled microfossil assemblages decline in diversity upsection, coincident with the appearance of VSMs and intermittent euxinia within the basin. Whether this pattern is due to preservational bias related to greater water depth or the higher TOC of upper Chuar rocks or instead reflects biotic turnover related to the spread of euxinic water masses in the basin is unknown.

The earliest known (Namurian A, E1) haplolepids (Osteichthyes: Actinopterygii)

1983 ◽  
Vol 74 (2) ◽  
pp. 69-78 ◽  
Author(s):  
Karen A. Lowney
Keyword(s):  
New Species ◽  
Geographical Distribution ◽  
Evolutionary History ◽  
Common Ancestor ◽  
Nomen Nudum ◽  
New Genera ◽  
Skull Roof ◽  
The Family ◽  
History Of ◽  
A New Species

ABSTRACTTwo new genera and species of haplolepids (Chondrostei), Protohaplolepis scotica and Blairolepis loanheadensis, are described from the ironstones of Loanhead, Midlothian (Namurian A, E1); this represents the earliest known record of the family. Protohaplolepis scotica (= Traquair's nomen nudum “Eurylepis scoticus”) shows many features in common with Westoll's hypothetical haplolepid “common ancestor X”, and is possibly ancestral to the Haplolepis–Microhaplolepis line within the family. Blairolepis loanheadensis, known only from a skull roof, shows greater similarities to Parahaplolepis and Pyritocephalus, but differs from these genera in having separate dermopterotics and parietals. Two subfamilies, the Haplolepinae and the Parahaplolepinae, are suggested to reflect the distinct evolutionary lines within the family.A new species, Parahaplolepis westolli, is also described from Newsham, Northumberland (Westphalian B). This species shows a close resemblance to the American species Parahaplolepis tuberculata from Linton, Ohio.A brief discussion of the evolutionary history of the family is presented, along with a summary of its stratigraphical and geographical distribution.

scholarly journals Uncovering hidden biodiversity: phylogeny and taxonomy of Physoderinae (Reduviidae, Heteroptera), with emphasis on Physoderes Westwood in the Oriental and Australasian regions

2017 ◽  
Author(s):  
Wei Song Hwang ◽  
Christiane Weirauch
Keyword(s):  
New Species ◽  
Cladistic Analysis ◽  
Great Majority ◽  
Morphological Diversity ◽  
Taxonomic Revision ◽  
Morphological Characters ◽  
New Genera ◽  
Genus Level ◽  
Biogeographic History ◽  
Distribution Ranges

The cryptic assassin bug subfamily Physoderinae is characterized by a distinctly uneven species and genus-level diversity across continents, but the lack of a phylogeny has so far precluded investigations into the biogeographic history of the group. Endemic Madagascan Physoderinae (11 of the 15 genera) exhibit broad morphological diversity, but the large (38 spp.) and seemingly uniform genus Physoderes is widely distributed across the Oriental and Australasian regions. The three remaining genera are small or even monotypic and restricted to the Neotropical (Cryptophysoderes, Leptophysoderes) and Afrotropical (Porcelloderes) regions. To investigate relationships among Physoderinae, with emphasis on the monophyly of the Madagascan fauna and the monophyly of Physoderes, we conducted a cladistic analysis based on 57 morphological characters and complete genus-level taxon sampling. We found that the Madagascan fauna is not monophyletic, indicating that the island was colonized more than once, although the great majority of Madagascan taxa are part of a single clade. Overall relationships are recovered as Afrotropical Porcelloderes + [(Neotropical Cryptophysoderes, Leptophysoderes) + (Madagascan, Oriental and Australasian taxa)]. Physoderes is shown to be polyphyletic and 3 new genera, Breviphysoderes gen. nov., Macrophysoderes gen. nov. and Nanophysoderes gen. nov., are erected to accommodate new species and several species previously classified as Physoderes. A taxonomic revision of Physoderes and allied genera is conducted. Diagnoses, updated distribution ranges, habitus and genitalic images, and identification keys are provided. A total of 17 synonymies are given, and 15 new species and 3 new genera are described, focusing on the diversity of Physoderinae in the Oriental and Australasian regions. The new species are Breviphysoderes fulvopicta gen. et sp. nov., B. tenebrosa gen. et sp. nov., Macrophysoderes cirripilosa gen. et sp. nov., M. elongata gen. et sp. nov., M. finisterre gen. et sp. nov., M. grandis gen. et sp. nov., Paraphysoderes popeye sp. nov., Physoderes anamalaiensis sp. nov., P. brevipennis sp. nov., P. minime sp. nov., P. muluensis sp. nov., P. mysorensis sp. nov., P. nigripennis sp. nov., P. ractepilosa sp. nov. and P. tricolor sp. nov.

Three new species, two new genera, and new family Biphragmosagittidae (Сhaetognatha) from Southwest Pacific Ocean

2011 ◽  
Vol 20 (1) ◽  
pp. 161-173
Author(s):  
A.P. Kassatkina
Keyword(s):  
New Species ◽  
Type Species ◽  
Morphological Characters ◽  
The Body ◽  
New Order ◽  
New Genera ◽  
New Family ◽  
The Family ◽  
Three New Species

Resuming published and own data, a revision of classification of Chaetognatha is presented. The family Sagittidae Claus & Grobben, 1905 is given a rank of subclass, Sagittiones, characterised, in particular, by the presence of two pairs of sac-like gelatinous structures or two pairs of fins. Besides the order Aphragmophora Tokioka, 1965, it contains the new order Biphragmosagittiformes ord. nov., which is a unique group of Chaetognatha with an unusual combination of morphological characters: the transverse muscles present in both the trunk and the tail sections of the body; the seminal vesicles simple, without internal complex compartments; the presence of two pairs of lateral fins. The only family assigned to the new order, Biphragmosagittidae fam. nov., contains two genera. Diagnoses of the two new genera, Biphragmosagitta gen. nov. (type species B. tarasovi sp. nov. and B. angusticephala sp. nov.) and Biphragmofastigata gen. nov. (type species B. fastigata sp. nov.), detailed descriptions and pictures of the three new species are presented.

scholarly journals A synthesis of African and western Indian Ocean Island mammal taxa (Class: Mammalia) described between 1988 and 2008: an update to Allen (1939) and Ansell (1989)

Zootaxa ◽  
2009 ◽  
Vol 2205 (1) ◽  
pp. 1-36 ◽  
Author(s):  
MICHAEL HOFFMANN ◽  
PETER GRUBB ◽  
COLIN P. GROVES ◽  
RAINER HUTTERER ◽  
ERIK VAN DER STRAETEN ◽  
...  
Keyword(s):  
New Species ◽  
Western Indian Ocean ◽  
Systematic Position ◽  
Iucn Red List ◽  
New Genera ◽  
New Subspecies ◽  
New Subgenus ◽  
African Mammals ◽  
The Status ◽  
Data Deficient

We provide a synthesis of all mammal taxa described from the African mainland, Madagascar and all surrounding islands in the 20 years since 1988, thereby supplementing the earlier works of G.M. Allen (1939) and W.F.H. Ansell (1989), and bringing the list of African mammals described over the last 250 years current to December 2008. We list 175 new extant taxa, including five new genera, one new subgenus, 138 new species and 31 new subspecies, including remarks, where relevant, on the current systematic position of each taxon. Names of seven species of primates are emended, according to the requirements of the ICZN. The taxonomic group in which the largest number of new taxa has been described is the Primates, with two new genera, 47 new species and 11 new subspecies, while geographically the biggest increase in new species descriptions has been on the island of Madagascar, accounting for roughly half (67) of all new species described in the past 20 years. Nearly half of all new species listed currently are assessed as Data Deficient on the IUCN Red List of Threatened Species (49 of 101 listed species) suggesting further research is urgently needed to help clarify the status of those recently described species.

scholarly journals A new lineage of mazaediate fungi in the Eurotiomycetes: Cryptocaliciomycetidae subclass. nov., based on the new species Cryptocalicium blascoi and the revision of the ascoma evolution

2021 ◽  
Vol 20 (7) ◽  
pp. 889-904
Author(s):  
M. Prieto ◽  
Javier Etayo ◽  
I. Olariaga
Keyword(s):  
New Species ◽  
Common Ancestor ◽  
External Surface ◽  
Evolutionary Relationships ◽  
New Order ◽  
Ancestral State ◽  
Multigene Phylogeny ◽  
State Reconstruction ◽  
Distinct Structure ◽  
Dark Violet

AbstractThe class Eurotiomycetes (Ascomycota, Pezizomycotina) comprises important fungi used for medical, agricultural, industrial and scientific purposes. Eurotiomycetes is a morphologically and ecologically diverse monophyletic group. Within the Eurotiomycetes, different ascoma morphologies are found including cleistothecia and perithecia but also apothecia or stromatic forms. Mazaediate representatives (with a distinct structure in which loose masses of ascospores accumulate to be passively disseminated) have evolved independently several times. Here we describe a new mazaediate species belonging to the Eurotiomycetes. The multigene phylogeny produced (7 gene regions: nuLSU, nuSSU, 5.8S nuITS, mtSSU, RPB1, RPB2 and MCM7) placed the new species in a lineage sister to Eurotiomycetidae. Based on the evolutionary relationships and morphology, a new subclass, a new order, family and genus are described to place the new species: Cryptocalicium blascoi. This calicioid species occurs on the inner side of loose bark strips of Cupressaceae (Cupressus, Juniperus). Morphologically, C. blascoi is characterized by having minute apothecioid stalked ascomata producing mazaedia, clavate bitunicate asci with hemiamyloid reaction, presence of hamathecium and an apothecial external surface with dark violet granules that becomes turquoise green in KOH. The ancestral state reconstruction analyses support a common ancestor with open ascomata for all deep nodes in Eurotiomycetes and the evolution of closed ascomata (cleistothecioid in Eurotiomycetidae and perithecioid in Chaetothyriomycetidae) from apothecioid ancestors. The appropriateness of the description of a new subclass for this fungus is also discussed.

scholarly journals Experimental evidence for yawn contagion in orangutans (Pongo pygmaeus)

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Evy van Berlo ◽  
Alejandra P. Díaz-Loyo ◽  
Oscar E. Juárez-Mora ◽  
Mariska E. Kret ◽  
Jorg J. M. Massen
Keyword(s):  
Experimental Evidence ◽  
Common Ancestor ◽  
Great Apes ◽  
Pongo Pygmaeus ◽  
Last Common Ancestor ◽  
Contagious Yawning ◽  
Proximate Mechanism ◽  
Social Species ◽  
Ultimate Causation

AbstractYawning is highly contagious, yet both its proximate mechanism(s) and its ultimate causation remain poorly understood. Scholars have suggested a link between contagious yawning (CY) and sociality due to its appearance in mostly social species. Nevertheless, as findings are inconsistent, CY’s function and evolution remains heavily debated. One way to understand the evolution of CY is by studying it in hominids. Although CY has been found in chimpanzees and bonobos, but is absent in gorillas, data on orangutans are missing despite them being the least social hominid. Orangutans are thus interesting for understanding CY’s phylogeny. Here, we experimentally tested whether orangutans yawn contagiously in response to videos of conspecifics yawning. Furthermore, we investigated whether CY was affected by familiarity with the yawning individual (i.e. a familiar or unfamiliar conspecific and a 3D orangutan avatar). In 700 trials across 8 individuals, we found that orangutans are more likely to yawn in response to yawn videos compared to control videos of conspecifics, but not to yawn videos of the avatar. Interestingly, CY occurred regardless of whether a conspecific was familiar or unfamiliar. We conclude that CY was likely already present in the last common ancestor of humans and great apes, though more converging evidence is needed.

scholarly journals New Recent foraminiferal genera and species from the lagoon at Madang, Papua New Guinea

1992 ◽  
Vol 11 (1) ◽  
pp. 85-93 ◽  
Author(s):  
Martin R. Langer
Keyword(s):  
New Species ◽  
Shallow Water ◽  
Papua New Guinea ◽  
New Guinea ◽  
Coarse Grained ◽  
New Genera ◽  
Low Oxygen ◽  
Shell Surface ◽  
Sedimentary Environments ◽  
Tropical Lagoon

Abstract. Two new genera and eight new species of benthic foraminifera are described from the shallow water, tropical lagoon of Madang, Papua New Guinea. The new hauerinid genus Pseudolachlanella is characterized by juvenile cryptoquinqueloculine, adult almost massiline arranged chambers, and a slitlike, curved aperture with parallel sides and a long, slender, curved miliolid tooth. Pitella haigi n. gen., n. sp. is a new foraminifera with cryptoquinqueloculine arranged chambers, an almost entirely pitted shell surface (pseudopores) and a rounded aperture with a short simple tooth. Among the other species described as new are four hauerinids and two agglutinated foraminifera All new species described here occur sporadically in the shallow water back- and forereef environments of the lagoon (0–55m), and live infaunally and epifaunally in well-oxygenated, fine and coarse grained biogenic sediments. They are absent in muddy, organic-rich, low-oxygen sedimentary environments within bay inlets where variations of salinity are considerable.

Sign in / Sign up

Export Citation Format

Share Document