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.

scholarly journals The palate and choanae structure of the cf. Susisuchus (Crocodyliformes, Eusuchia): phylogenetic implications

2018 ◽  
Author(s):  
Karla J Leite ◽  
Daniel C Fortier
Keyword(s):  
Lower Cretaceous ◽  
Evolutionary History ◽  
Ventral View ◽  
Sister Group ◽  
Phylogenetic Position ◽  
Phylogenetic Implications ◽  
History Of

Crocodyliformes have undergone few modifications in their morphology since they have emerged. The change in the position of the choana was important during the evolutionary history of this group. Such character is relevant in the phylogenetic position of many crocodyliforms. The Susisuchidae clade has been placed in different phylogenetic positions: as a sister group of Eusuchia, advanced Neosuchia and in Eusuchia. In Isisfordia there are reports that the choana of this taxon is or not fully enclosed by pterygoid. A new skull of cf. Susisuchus from the Crato Formation of the Santana Group (Lower Cretaceous) is described and we recover Susisuchidae in a new phylogenetic position within Eusuchia. The preservation in the ventral view of FPH-243-V allows character encoding not yet observed for the species. The new specimen shows a typical eusuchian palate for Susisuchus, in which the choana is fully enclosed by the pterygoid. The encoding of the ventral characters of Susisuchus places Susisuchidae in Eusuchia. However, this position must be further studied, since the matrices showed fragility in the reconstitution of the Neosuchia-Eusuchia transition.

scholarly journals The palate and choanae structure of the cf. Susisuchus (Crocodyliformes, Eusuchia): phylogenetic implications

2018 ◽  
Author(s):  
Karla J Leite ◽  
Daniel C Fortier
Keyword(s):  
Lower Cretaceous ◽  
Evolutionary History ◽  
Ventral View ◽  
Sister Group ◽  
Phylogenetic Position ◽  
Phylogenetic Implications ◽  
History Of

Crocodyliformes have undergone few modifications in their morphology since they have emerged. The change in the position of the choana was important during the evolutionary history of this group. Such character is relevant in the phylogenetic position of many crocodyliforms. The Susisuchidae clade has been placed in different phylogenetic positions: as a sister group of Eusuchia, advanced Neosuchia and in Eusuchia. In Isisfordia there are reports that the choana of this taxon is or not fully enclosed by pterygoid. A new skull of cf. Susisuchus from the Crato Formation of the Santana Group (Lower Cretaceous) is described and we recover Susisuchidae in a new phylogenetic position within Eusuchia. The preservation in the ventral view of FPH-243-V allows character encoding not yet observed for the species. The new specimen shows a typical eusuchian palate for Susisuchus, in which the choana is fully enclosed by the pterygoid. The encoding of the ventral characters of Susisuchus places Susisuchidae in Eusuchia. However, this position must be further studied, since the matrices showed fragility in the reconstitution of the Neosuchia-Eusuchia transition.

The skeletal morphology of the solemydid turtleNaomichelys speciosafrom the Early Cretaceous of Texas

2014 ◽  
Vol 88 (6) ◽  
pp. 1257-1287 ◽  
Author(s):  
Walter G. Joyce ◽  
Juliana Sterli ◽  
Sandra D. Chapman
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Lower Cretaceous ◽  
Fossil Record ◽  
Posterior Margin ◽  
Late Jurassic ◽  
Evolutionary History ◽  
Ventral View ◽  
Skeletal Morphology ◽  
History Of

The fossil record of solemydid turtles is primarily based on isolated fragments collected from Late Jurassic to Late Cretaceous sediments throughout North America and Europe and little is therefore known about the morphology and evolutionary history of the group. We here provide a detailed description of the only known near-complete solemydid skeleton, which was collected from the Lower Cretaceous (Aptian–Albian) Antlers Formation of Texas during the mid-twentieth century, but essentially remains undescribed to date. Though comparison is limited, the skeleton is referred toNaomichelys speciosa, which is based on an isolated entoplastron from the Lower Cretaceous (Aptian–Albian) Kootenai (Cloverly) Formation of Montana. The absence of temporal emarginations, contribution of the jugals to the orbits, and a clear subdivision of the middle and inner cavities, and the presence of elongate postorbitals, posteriorly expanded squamosals, a triangular fossa at the posterior margin of the squamosals, an additional pair of tubercula basioccipitale that is formed by the pterygoids, foramina pro ramo nervi vidiani (VII) that are visible in ventral view, shell sculpturing consisting of high tubercles, a large entoplastron with entoplastral scute, V-shaped anterior peripherals, and limb osteoderms with tubercular sculpture diagnoseNaomichelys speciosaas a representative of Solemydidae. The full visibility of the parabasisphenoid complex in ventral view, the presence of an expanded symphyseal shelf, and the unusual ventromedial folding of the coronoid process are the primary characteristics that distinguishNaomichelys speciosafrom the near-coeval European taxonHelochelydra nopcsai.

scholarly journals New material of the ‘microsaur’ Llistrofus from the cave deposits of Richards Spur, Oklahoma and the paleoecology of the Hapsidopareiidae

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6327 ◽  
Author(s):  
Bryan M. Gee ◽  
Joseph J. Bevitt ◽  
Ulf Garbe ◽  
Robert R. Reisz
Keyword(s):  
Evolutionary History ◽  
Substantial Reduction ◽  
Sister Group ◽  
Phylogenetic Position ◽  
Neutron Tomography ◽  
Early Permian ◽  
Cave Deposits ◽  
Internal Structures ◽  
History Of ◽  
New Material

The Hapsidopareiidae is a group of “microsaurs” characterized by a substantial reduction of several elements in the cheek region that results in a prominent, enlarged temporal emargination. The clade comprises two markedly similar taxa from the early Permian of Oklahoma, Hapsidopareion lepton and Llistrofus pricei, which have been suggested to be synonymous by past workers. Llistrofus was previously known solely from the holotype found near Richards Spur, which consists of a dorsoventrally compressed skull in which the internal structures are difficult to characterize. Here, we present data from two new specimens of Llistrofus. This includes data collected through the use of neutron tomography, which revealed important new details of the palate and the neurocranium. Important questions within “Microsauria” related to the evolutionary transformations that likely occurred as part of the acquisition of the highly modified recumbirostran morphology for a fossorial ecology justify detailed reexamination of less well-studied taxa, such as Llistrofus. Although this study eliminates all but one of the previous features that differentiated Llistrofus and Hapsidopareion, the new data and redescription identify new features that justify the maintained separation of the two hapsidopareiids. Llistrofus possesses some of the adaptations for a fossorial lifestyle that have been identified in recumbirostrans but with a lesser degree of modification (e.g., reduced neurocranial ossification and mandibular modification). Incorporating the new data for Llistrofus into an existing phylogenetic matrix maintains the Hapsidopareiidae’s (Llistrofus + Hapsidopareion) position as the sister group to Recumbirostra. Given its phylogenetic position, we contextualize Llistrofus within the broader “microsaur” framework. Specifically, we propose that Llistrofus may have been fossorial but was probably incapable of active burrowing in the fashion of recumbirostrans, which had more consolidated and reinforced skulls. Llistrofus may represent an earlier stage in the step-wise acquisition of the derived recumbirostran morphology and paleoecology, furthering our understanding of the evolutionary history of “microsaurs.”

scholarly journals A new phosphatized ophiuroid from the lower Triassic of Nevada and its position in the evolutionary history of the Ophiuroidea (Echinodermata)

Zootaxa ◽  
2021 ◽  
Vol 5071 (3) ◽  
pp. 369-383
Author(s):  
BEN THUY ◽  
VIVIENNE MAXWELL ◽  
SARA B. PRUSS
Keyword(s):  
Fossil Record ◽  
Evolutionary History ◽  
Lower Triassic ◽  
Phylogenetic Inference ◽  
Phylogenetic Position ◽  
Acid Extraction ◽  
Early Triassic ◽  
New Taxon ◽  
History Of ◽  
Bayesian Phylogenetic Inference

The Lower Triassic fossil record of brittle stars is relatively rich, yet most records published to date are based on poorly preserved or insufficiently known fossils. This hampers exhaustive morphological analyses, comparison with recent relatives or inclusion of Early Triassic ophiuroid taxa in phylogenetic estimates. Here, we describe a new ophiuroid from the Lower Triassic of Nevada, preserved as phosphatized skeletal parts and assigned to the new taxon Ophiosuperstes praeparvus gen. et sp. nov Maxwell, V. & Pruss. S.B. This unusual preservation of the fossils allowed for acid-extraction of an entire suite of dissociated skeletal parts, including lateral arm plates, ventral arm plates, vertebrae and various disk plates, thus unlocking sufficient morphological information to explore the phylogenetic position of the new taxon. Bayesian phylogenetic inference suggests a basalmost position of O. praeparvus within the Ophintegrida, sister to all other sampled members of that superorder. The existence of coeval but more derived ophiuroids suggests that O. praeparvus probably represents a member of a more ancient stem ophintegrid group persisting into the Early Triassic.  

scholarly journals Nephromyces represents a diverse and novel lineage of the Apicomplexa that has retained apicoplasts

2019 ◽  
Author(s):  
Sergio A Muñoz-Gómez ◽  
Keira Durnin ◽  
Laura Eme ◽  
Christopher Paight ◽  
Christopher E Lane ◽  
...  
Keyword(s):  
Life Style ◽  
Metabolic Pathways ◽  
Evolutionary History ◽  
Phylogenetic Analyses ◽  
Phylogenetic Position ◽  
Biosynthetic Pathways ◽  
History Of ◽  
Sea Squirts ◽  
Shed Light ◽  
Apicoplast Genome

Abstract A most interesting exception within the parasitic Apicomplexa is Nephromyces, an extracellular, probably mutualistic, endosymbiont found living inside molgulid ascidian tunicates (i.e., sea squirts). Even though Nephromyces is now known to be an apicomplexan, many other questions about its nature remain unanswered. To gain further insights into the biology and evolutionary history of this unusual apicomplexan, we aimed to (1) find the precise phylogenetic position of Nephromyces within the Apicomplexa, (2) search for the apicoplast genome of Nephromyces, and (3) infer the major metabolic pathways in the apicoplast of Nephromyces. To do this, we sequenced a metagenome and a metatranscriptome from the molgulid renal sac, the specialized habitat where Nephromyces thrives. Our phylogenetic analyses of conserved nucleus-encoded genes robustly suggest that Nephromyces is a novel lineage sister to the Hematozoa, which comprises both the Haemosporidia (e.g., Plasmodium) and the Piroplasmida (e.g., Babesia and Theileria). Furthermore, a survey of the renal sac metagenome revealed 13 small contigs that closely resemble the genomes of the non-photosynthetic reduced plastids, or apicoplasts, of other apicomplexans. We show that these apicoplast genomes correspond to a diverse set of most closely related but genetically divergent Nephromyces lineages that co-inhabit a single tunicate host. In addition, the apicoplast of Nephromyces appears to have retained all biosynthetic pathways inferred to have been ancestral to parasitic apicomplexans. Our results shed light on the evolutionary history of the only probably mutualistic apicomplexan known, Nephromyces, and provide context for a better understanding of its life style and intricate symbiosis.

Phylogenetic position and evolutionary history of the turtle and whale barnacles (Cirripedia: Balanomorpha: Coronuloidea)

2013 ◽  
Vol 67 (1) ◽  
pp. 9-14 ◽  
Author(s):  
Ryota Hayashi ◽  
Benny K.K. Chan ◽  
Noa Simon-Blecher ◽  
Hiromi Watanabe ◽  
Tamar Guy-Haim ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Phylogenetic Position ◽  
History Of

A fossil record of land plant origins from charophyte algae

Science ◽  
2021 ◽  
Vol 373 (6556) ◽  
pp. 792-796 ◽  
Author(s):  
Paul K. Strother ◽  
Clinton Foster
Keyword(s):  
Fossil Record ◽  
Evolutionary History ◽  
Phylogenetic Signal ◽  
Land Plant ◽  
Fossil Plants ◽  
Fossil Plant ◽  
Molecular Phylogenetic ◽  
History Of ◽  
Time Gap ◽  
Evolutionary Continuity

Molecular time trees indicating that embryophytes originated around 500 million years ago (Ma) during the Cambrian are at odds with the record of fossil plants, which first appear in the mid-Silurian almost 80 million years later. This time gap has been attributed to a missing fossil plant record, but that attribution belies the case for fossil spores. Here, we describe a Tremadocian (Early Ordovician, about 480 Ma) assemblage with elements of both Cambrian and younger embryophyte spores that provides a new level of evolutionary continuity between embryophytes and their algal ancestors. This finding suggests that the molecular phylogenetic signal retains a latent evolutionary history of the acquisition of the embryophytic developmental genome, a history that perhaps began during Ediacaran-Cambrian time but was not completed until the mid-Silurian (about 430 Ma).

scholarly journals Experimental degradation of helicoidal photonic nanostructures in scarab beetles (Coleoptera: Scarabaeidae): implications for the identification of circularly polarizing cuticle in the fossil record

2018 ◽  
Vol 15 (148) ◽  
pp. 20180560 ◽  
Author(s):  
Giliane P. Odin ◽  
Maria E. McNamara ◽  
Hans Arwin ◽  
Kenneth Järrendahl
Keyword(s):  
Uric Acid ◽  
Fossil Record ◽  
Evolutionary History ◽  
Polarized Light ◽  
Circularly Polarized Light ◽  
Circularly Polarized ◽  
Alkaline Conditions ◽  
History Of ◽  
Diagenetic History ◽  
Scarab Beetles

Scarab beetles (Coleoptera: Scarabaeidae) can exhibit striking colours produced by pigments and/or nanostructures. The latter include helicoidal (Bouligand) structures that can generate circularly polarized light. These have a cryptic evolutionary history in part because fossil examples are unknown. This suggests either a real biological signal, i.e. that Bouligand structures did not evolve until recently, or a taphonomic signal, i.e. that conditions during the fossilization process were not conducive to their preservation. We address this issue by experimentally degrading circularly polarizing cuticle of modern scarab beetles to test the relative roles of decay, maturation and taxonomy in controlling preservation. The results reveal that Bouligand structures have the potential to survive fossilization, but preservation is controlled by taxonomy and the diagenetic history of specimens. Further, cuticle of specific genus ( Chrysina ) is particularly decay-prone in alkaline conditions; this may relate to the presence of certain compounds, e.g. uric acid, in the cuticle of these taxa.

scholarly journals Three new Cenomanian conifers from El Chango (Chiapas, Mexico) offer a snapshot of the geographic mosaic of the Mesozoic conifer decline

2021 ◽  
Author(s):  
Ixchel Gonzalez-Ramirez ◽  
Sergio RS Cevallos-Ferriz ◽  
Carl Rothfels
Keyword(s):  
Evolutionary History ◽  
Mixed Forest ◽  
Freshwater Ecosystems ◽  
Total Evidence ◽  
Morphological Data ◽  
Phylogenetic Position ◽  
Dominant Group ◽  
Geographic Mosaic ◽  
History Of ◽  
Rare Opportunity

Premise of study: El Chango is a recently discovered quarry that contains extremely well preserved fossils. The Cenomanian age of the locality corresponds to a time when the global flora was transitioning from gymnosperm- to angiosperm-dominated, yet conifers predominate in this locality. These fossils thus provide a rare opportunity to understand the replacement of conifers by angiosperms as the dominant group of plants. Methods: We collected material from El Chango in annual expeditions (2010 to 2014). We selected the three most abundant and best preserved conifer morphotypes and conducted a total-evidence (i.e., including molecular and morphological data) phylogenetic analysis of a sample of 72 extant conifer species plus the three fossils. We use these results to inform our taxonomic decisions. Results: We obtained four equally most-parsimonious trees (consistency index = 44.1%, retention index = 78.8%). Despite ambiguous relationships among some extant taxa, the three fossil conifers had the same phylogenetic position in all four most parsimonious trees; we describe these species as new: Sequoiadendron helicalancifolium sp. nov. (Cupressaceae), and Microcachrys rhomboidea sp. nov. and Dacrydium bifoliosus sp. nov (Podocarpaceae). The ecosystem is interpreted as a coastal humid mixed forest. Conclusions: Our findings contribute to the understanding of Cenomanian equatorialregions, and support the hypothesis of a geographically and ecologically structured rise of angiosperms, with conifers remaining dominant in brackish-water and angiosperms becoming dominant in freshwater-ecosystems. These fossils fill in gaps in the evolutionary history of lineages like Microcachrys, which we demonstrate occurred in the Northern hemisphere before becoming restricted to its current range (Tasmania).

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