scholarly journals Canadia spinosa and the early evolution of the annelid nervous system

2019 ◽  
Vol 5 (9) ◽  
pp. eaax5858 ◽  
Author(s):  
Luke Parry ◽  
Jean-Bernard Caron
Keyword(s):  
Phylogenetic Analysis ◽  
Nervous System ◽  
Fossil Record ◽  
Morphological Diversity ◽  
Sister Group ◽  
Early Evolution ◽  
Phylogenetic Position ◽  
Early Cambrian ◽  
Burgess Shale ◽  
Rapid Diversification

Annelid worms are a disparate, primitively segmented clade of bilaterians that first appear during the early Cambrian Period. Reconstructing their early evolution is complicated by the extreme morphological diversity in early diverging lineages, rapid diversification, and sparse fossil record. Canadia spinosa, a Burgess Shale fossil polychaete, is redescribed as having palps with feeding grooves, a dorsal median antenna and biramous parapodia associated with the head and flanking a ventral mouth. Carbonaceously preserved features are identified as a terminal brain, circumoral connectives, a midventral ganglionated nerve cord and prominent parapodial nerves. Phylogenetic analysis recovers neuroanatomically simple extant taxa as the sister group of other annelids, but the phylogenetic position of Canadia suggests that the annelid ancestor was reasonably complex neuroanatomically and that reduction of the nervous system occurred several times independently in the subsequent 500 million years of annelid evolution.

Phylogenetic analysis of the Neotropical Pristimantis leptolophus species group (Anura: Craugastoridae): molecular approach and description of a new polymorphic species 

Zootaxa ◽  
2017 ◽  
Vol 4242 (2) ◽  
pp. 313
Author(s):  
MAURICIO RIVERA-CORREA ◽  
CARLOS JIMÉNEZ-RIVILLAS ◽  
JUAN M. DAZA
Keyword(s):  
Phylogenetic Analysis ◽  
Phylogenetic Reconstruction ◽  
Morphological Diversity ◽  
Molecular Data ◽  
Species Group ◽  
Morphological Data ◽  
Phylogenetic Position ◽  
Molecular Evidence ◽  
Polymorphic Species ◽  
Species Groups

Pristimantis, distributed throughout the New World tropics, is the most speciose vertebrate genus. Pristimantis presents an enormous morphological diversity and is currently divided into several demonstrably non-monophyletic phenetic species groups. With the purpose of increasing our understanding of Pristimantis systematics, we present the first phylogenetic analysis using molecular evidence to test the monophyly and infer evolutionary relationships within the Pristimantis leptolophus group, an endemic group of frogs from the highlands of the Colombian Andes. Our phylogenetic reconstruction recovers the group as monophyletic with high support, indicating general concordance between molecular data and morphological data. In addition, we describe a new polymorphic species lacking conspicuous tubercles, a regular attribute among species of the P. leptolophus species group and endemic from the Páramo de Sonsón complex (Antioquia, Colombia). The phylogenetic position of the new species is inferred and other systematic implications in the light of our results are discussed. 

A new arthropod Pygmaclypeatus daziensis from the Early Cambrian Chengjiang Lagerstätte, South China

2000 ◽  
Vol 74 (5) ◽  
pp. 979-982 ◽  
Author(s):  
Xingliang Zhang ◽  
Jian Han ◽  
Degan Shu
Keyword(s):  
South China ◽  
Fossil Record ◽  
South Australia ◽  
Early Cambrian ◽  
Burgess Shale ◽  
Closely Related Species ◽  
Stratigraphic Position ◽  
Chengjiang Lagerstätte ◽  
Early Metazoan ◽  
North Greenland

The early Cambrian Chengjiang Lagerstatte, generally regarded as late Atdabanian (Qian and Bengtson, 1989; Bengtson et al., 1990), has become celebrated for perhaps the earliest biota of soft-bodied organisms known from the fossil record and has proven to be critical to our understanding of early metazoan evolution. The Sirius Passet fauna from Peary Land, North Greenland, another important repository of soft-bodied and poorly sclerotized fossils, was also claimed as Early Cambrian (Conway Morris et al., 1987; Budd, 1995). The exact stratigraphic position of the Sirius Passet fauna (Buen Formation) is still uncertain, although the possibility of late Atdabanian age was proposed (Vidal and Peel, 1993). Recent work dates it in the “Nevadella” Biozone (Budd and Peel, 1998). It therefore appears to be simultaneous with or perhaps slightly younger than Chengjiang Lagerstatte, Eoredlichia Biozone (Zhuravlev, 1995). The Emu Bay Shale of Kangaroo Island, South Australia, has long been famous as a source of magnificent specimens of the trilobites Redlichia takooensis and Hsunaspis bilobata. It is additionally important as the only site in Australia so far to yield a Burgess-Shale-type biota (Glaessner, 1979; Nedin, 1992). The Emu Bay Shale was considered late Early Cambrian in age (Daily, 1956; Öpik, 1975). But Zhang et al.(1980) reassessed its age based on data from the Chinese Early Cambrian. The occurrence of Redlichia takooensis and closely related species of Hsunaspis indicates an equivalence to the Tsanglangpuian in the Chinese sequence, and the contemporary South Australia fauna correlate with the Botomian of Siberia (Bengtson et al., 1990). Thus the Emu Bay Shale is younger than the upper Atdabanian Chengjiang Lagerstatte, Chiungchussuian.

Phylogenetic position of Aerumnosa Mohrig (Diptera, Sciaridae) as revealed by multigene analysis, with the description of four new Oriental species

Zootaxa ◽  
2018 ◽  
Vol 4399 (2) ◽  
pp. 248 ◽  
Author(s):  
PEKKA VILKAMAA ◽  
HANS-GEORG RUDZINSKI ◽  
NIKOLA BURDÍKOVÁ ◽  
JAN ŠEVČÍK
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Papua New Guinea ◽  
Sister Group ◽  
Phylogenetic Position ◽  
Phylogenetic Hypothesis ◽  
Gene Markers ◽  
Multigene Analysis ◽  
Molecular Phylogenetic ◽  
New Material

Four Oriental species of Aerumnosa Mohrig, 1999 (Diptera: Sciaridae), a genus previously known only from Papua New Guinea, are newly described and illustrated: Aerumnosa bituberculata sp. n. (India), A. gemmifera sp. n. (Malaysia: Sabah), A. horrifica sp. n. (Brunei, Thailand) and A. impar sp. n. (Malaysia: Sabah). On the basis of the new material, the genus is redefined. A key to the known species of Aerumnosa is presented, including four new species. An updated molecular phylogenetic analysis based on four gene markers (18S, 28S, 16S and COI) shows Aerumnosa to be a member of the subfamily Cratyninae. The monophyly of Cratyninae is well supported, which clade also includes the genera Hyperlasion Schmitz, 1919, Pnyxiopalpus Vilkamaa & Hippa, 1999 and Pseudoaerumnosa Rudzinski, 2006. According to the present phylogenetic hypothesis, the monophyly of Cratyna Winnertz, 1967 s. l. needs to be revisited. The clade including Cratyna (s. str.) ambigua (Lengersdorf, 1934) appears as the sister group of Aerumnosa. 

scholarly journals A new Early Permian reptile and its significance in early diapsid evolution

2011 ◽  
Vol 278 (1725) ◽  
pp. 3731-3737 ◽  
Author(s):  
Robert R. Reisz ◽  
Sean P. Modesto ◽  
Diane M. Scott
Keyword(s):  
Phylogenetic Analysis ◽  
Fossil Record ◽  
Sedimentary Rocks ◽  
Sister Group ◽  
Flood Plain ◽  
Middle Permian ◽  
Lower Permian ◽  
Early Permian ◽  
Terrestrial Vertebrate

The initial stages of evolution of Diapsida (the large clade that includes not only snakes, lizards, crocodiles and birds, but also dinosaurs and numerous other extinct taxa) is clouded by an exceedingly poor Palaeozoic fossil record. Previous studies had indicated a 38 Myr gap between the first appearance of the oldest diapsid clade (Araeoscelidia), ca 304 million years ago (Ma), and that of its sister group in the Middle Permian ( ca 266 Ma). Two new reptile skulls from the Richards Spur locality, Lower Permian of Oklahoma, represent a new diapsid reptile: Orovenator mayorum n. gen. et sp. A phylogenetic analysis identifies O. mayorum as the oldest and most basal member of the araeoscelidian sister group. As Richards Spur has recently been dated to 289 Ma, the new diapsid neatly spans the above gap by appearing 15 Myr after the origin of Diapsida. The presence of O. mayorum at Richards Spur, which records a diverse upland fauna, suggests that initial stages in the evolution of non-araeoscelidian diapsids may have been tied to upland environments. This hypothesis is consonant with the overall scant record for non-araeoscelidian diapsids during the Permian Period, when the well-known terrestrial vertebrate communities are preserved almost exclusively in lowland deltaic, flood plain and lacustrine sedimentary rocks.

scholarly journals New mid-Cretaceous cryptic slime mold beetles and the early evolution of Sphindidae (Coleoptera: Cucujoidea)

2021 ◽  
Vol 79 ◽  
pp. 587-597
Author(s):  
Yan-Da Li ◽  
Erik Tihelka ◽  
Zhen-Hua Liu ◽  
Di-Ying Huang ◽  
Chen‑Yang Cai
Keyword(s):  
Phylogenetic Analysis ◽  
Fossil Record ◽  
Slime Mold ◽  
Early Evolution ◽  
Calibration Point ◽  
Crown Group ◽  
Slime Molds ◽  
The Family ◽  
Group Members

Abstract The cryptic slime mold beetles, Sphindidae, are a moderately diverse cucujoid beetle family, whose members are obligately tied to slime molds throughout their life. The fossil record of sphindid beetles is sparse; stem-sphindids and crown-group members of uncertain systematic placement have been reported from Cretaceous ambers. Here we review the Mesozoic fossil record of Sphindidae and report a new sphindid genus and species, Trematosphindus newtonigen. et sp. nov., from Albian/Cenomanian amber from northern Myanmar (ca. 99 Ma). Trematosphindus is set apart from all other sphindids by the presence of distinct lateral cavities on the anterior pronotal angles. Our phylogenetic analysis identifies Trematosphindus as an early-diverging genus within Sphindidae, sister to the remainder of the family except Protosphindus, or Protosphindus and Odontosphindus. The new fossils provide evidence that basal crown slime mold beetles begun to diversify by the mid-Cretaceous, providing a valuable calibration point for understanding timescale of sphindid co-evolution with slime molds.

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.

Alotanypus vittigera (Edwards) comb. nov.: adult redescription, immature description and a phylogenetic analysis of the genus (Diptera: Chironomidae: Tanypodinae)

Zootaxa ◽  
2011 ◽  
Vol 2795 (1) ◽  
pp. 46 ◽  
Author(s):  
AUGUSTO SIRI ◽  
MARIANO DONATO ◽  
GERMÁN ORPELLA ◽  
Julieta Massaferro
Keyword(s):  
Phylogenetic Analysis ◽  
Cladistic Analysis ◽  
Sister Group ◽  
Phylogenetic Position ◽  
Phylogenetic Hypothesis ◽  
Male And Female

Anatopynia vittigera Edwards is transfered to Alotanypus. The male and female of A. vittigera comb. nov. are redescribed and immatures are described and illustrated. A cladistic analysis including one species of each Macropelopiini genus was conducted in order to assess the phylogenetic position of Alotanypus and to provide the first phylogenetic hypothesis for the genus. Adults and immatures were included in the analysis where discrete and continuos characters were considered. The cladistic analysis demonstrated that Alotanypus is a monophyletic genus, with Guassutanypus oliveirai as the sister group.

scholarly journals Phylogeny and Biogeography of the Enigmatic Ghost Lineage Cylindrotomidae (Diptera: Nematocera)

2021 ◽  
Author(s):  
Iwona Kania-Kłosok ◽  
André Nel ◽  
Jacek Szwedo ◽  
Wiktoria Jordan-Stasiło ◽  
Wiesław Krzemiński
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Comparative Analysis ◽  
Sister Group ◽  
Phylogenetic Position ◽  
Crown Group ◽  
Extant Genus ◽  
Stem Group ◽  
Two New Species ◽  
Fossil Genus

Abstract Ghost lineages have always challenged the understanding of organism evolution. They participate in misinterpretations in phylogenetic, clade dating, biogeographic, and paleoecologic studies. They directly result from fossilization biases and organism biology. The Cylindrotomidae are a perfect example of an unexplained ghost lineage during the Mesozoic, as its sister family Tipulidae is already well diversified during the Cretaceous, while the oldest Cylindrotomidae are Paleogene representatives of the extant genus Cylindrotoma and of the enigmatic fossil genus Cyttaromyia. Here We clarify the phylogenetic position of Cyttaromyia in the stem group of the whole family, suggesting that the crown group of the Cylindrotomidae began to diversify during the Cenozoic, unlike their sister group Tipulidae. We make a comparative analysis of all species in Cyttaromyia, together with the descriptions of the two new species, C. gelhausi sp. nov. and C. freiwaldi sp. nov., and the revision of C. obdurescens. The cylindrotomid biogeography seems to be incongruent with the phylogenetic analysis, the apparently most derived subfamily Stibadocerinae having apparently a ‘Gondwanan’ distribution, with some genera only known from Australia or Chile, while the most inclusive Cylindrotominae are Holarctic.

scholarly journals The palate and choanae structure of theSusisuchusanatoceps(Crocodyliformes, Eusuchia): phylogenetic implications

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5372 ◽  
Author(s):  
Karla J. Leite ◽  
Daniel C. Fortier
Keyword(s):  
Lower Cretaceous ◽  
Fossil Record ◽  
Evolutionary History ◽  
Morphological Changes ◽  
Ventral View ◽  
Structural Evolution ◽  
Sister Group ◽  
Phylogenetic Position ◽  
Phylogenetic Implications ◽  
History Of

Crocodyliformes is a group with a broad fossil record, in which several morphological changes have been documented. Among known transformations the most iconic is perhaps the series of changes seen in the structural evolution of the choanae. The change in the position of the choanae was important during the evolutionary history of the Crocodyliformes. This structure is relevant in the phylogenetic position of many crocodyliforms. The new skull ofSusisuchus anatocepsfrom the Crato Formation of the Santana Group (Lower Cretaceous) is described and the preservation in the ventral view allows character encoding not yet observed for the species. The new specimen shows a typical eusuchian palate forSusisuchus anatoceps, in which the choana is fully enclosed by the pterygoid. The Susisuchidae clade has been placed in different phylogenetic positions: as a sister group of Eusuchia, advanced Neosuchia and in Eusuchia. InIsisfordiathere are reports that the choana of this taxon is or is not fully enclosed by the pterygoid. The encoding of the ventral characters ofS.anatocepsplaces Susisuchidae in Eusuchia. However, this position must be further studied, since the matrices showed fragility in the reconstitution of the Neosuchia–Eusuchia transition.

Phylogenetic position of the enigmatic termite family Stylotermitidae (Insecta : Blattodea)

2018 ◽  
Vol 32 (5) ◽  
pp. 1111 ◽  
Author(s):  
Li-Wei Wu ◽  
Thomas Bourguignon ◽  
Jan Šobotník ◽  
Ping Wen ◽  
Wei-Ren Liang ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Sister Group ◽  
Systematic Position ◽  
Developmental Pathways ◽  
Molecular Phylogenetic Analysis ◽  
Phylogenetic Position ◽  
Pheromone Communication ◽  
Eusocial Insects ◽  
Molecular Phylogenetic

Termites are eusocial insects currently classified into nine families, of which only Stylotermitidae has never been subjected to any molecular phylogenetic analysis. Stylotermitids present remarkable morphology and have the unique habit of feeding on living trees. We sequenced mitogenomes of five stylotermitid samples from China and Taiwan to reconstruct the phylogenetic position of Stylotermitidae. Our analyses placed Stylotermitidae as the sister group of all remaining Neoisoptera. The systematic position of Stylotermitidae calls for additional studies of their biology, including their developmental pathways and pheromone communication, which have the potential to change our understanding of termite evolution.

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