scholarly journals A tardigrade in Dominican amber

2021 ◽  
Vol 288 (1960) ◽  
Author(s):  
Marc A. Mapalo ◽  
Ninon Robin ◽  
Brendon E. Boudinot ◽  
Javier Ortega-Hernández ◽  
Phillip Barden
Keyword(s):  
North America ◽  
Fossil Record ◽  
Evolutionary History ◽  
Global Distribution ◽  
Molecular Clocks ◽  
Extreme Conditions ◽  
Diverse Group ◽  
Crown Group ◽  
Dominican Amber ◽  
Terrestrial Environments

Tardigrades are a diverse group of charismatic microscopic invertebrates that are best known for their ability to survive extreme conditions. Despite their long evolutionary history and global distribution in both aquatic and terrestrial environments, the tardigrade fossil record is exceedingly sparse. Molecular clocks estimate that tardigrades diverged from other panarthropod lineages before the Cambrian, but only two definitive crown-group representatives have been described to date, both from Cretaceous fossil deposits in North America. Here, we report a third fossil tardigrade from Miocene age Dominican amber. Paradoryphoribius chronocaribbeus gen. et sp. nov. is the first unambiguous fossil representative of the diverse superfamily Isohypsibioidea, as well as the first tardigrade fossil described from the Cenozoic. We propose that the patchy tardigrade fossil record can be explained by the preferential preservation of these microinvertebrates as amber inclusions, coupled with the scarcity of fossiliferous amber deposits before the Cretaceous.

scholarly journals Climbing since the early Miocene: The fossil record of Paullinieae (Sapindaceae)

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0248369
Author(s):  
Nathan A. Jud ◽  
Sarah E. Allen ◽  
Chris W. Nelson ◽  
Carolina L. Bastos ◽  
Joyce G. Chery
Keyword(s):  
North America ◽  
Fossil Record ◽  
Panama Canal ◽  
Herbarium Specimens ◽  
Western North America ◽  
Crown Group ◽  
Fossil Leaves ◽  
The Family ◽  
Cambial Variant ◽  
The Tropics

Paullinieae are a diverse group of tropical and subtropical climbing plants that belong to the soapberry family (Sapindaceae). The six genera in this tribe make up approximately one-quarter of the species in the family, but a sparse fossil record limits our understanding of their diversification. Here, we provide the first description of anatomically preserved fossils of Paullinieae and we re-evaluate other macrofossils that have been attributed to the tribe. We identified permineralized fossil roots in collections from the lower Miocene Cucaracha Formation where it was exposed along the Culebra Cut of the Panama Canal. We prepared the fossils using the cellulose acetate peel technique and compared the anatomy with that of extant Paullinieae. The fossil roots preserve a combination of characters found only in Paullinieae, including peripheral secondary vascular strands, vessel dimorphism, alternate intervessel pitting with coalescent apertures, heterocellular rays, and axial parenchyma strands of 2–4 cells, often with prismatic crystals. We also searched the paleontological literature for other occurrences of the tribe. We re-evaluated leaf fossils from western North America that have been assigned to extant genera in the tribe by comparing their morphology to herbarium specimens and cleared leaves. The fossil leaves that were assigned to Cardiospermum and Serjania from the Paleogene of western North America are likely Sapindaceae; however, they lack diagnostic characters necessary for inclusion in Paullinieae and should be excluded from those genera. Therefore, the fossils described here as Ampelorhiza heteroxylon gen. et sp. nov. are the oldest macrofossil evidence of Paullinieae. They provide direct evidence of the development of a vascular cambial variant associated with the climbing habit in Sapindaceae and provide strong evidence of the diversification of crown-group Paullinieae in the tropics by 18.5–19 million years ago.

scholarly journals The First Fossil Owl (Aves, Strigiformes) From the Paleogene of Africa

Diversity ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 163
Author(s):  
N. Adam Smith ◽  
Thomas A. Stidham ◽  
Jonathan S. Mitchell
Keyword(s):  
North America ◽  
Fossil Record ◽  
Evolutionary History ◽  
Ecological Role ◽  
Avian Predator ◽  
First Occurrence ◽  
Stark Contrast

The relatively extensive fossil record of owls (Aves, Strigiformes) in North America and Europe stands in stark contrast to the paucity of fossil strigiformes from Africa. The first occurrence of a fossil owl from the Paleogene of Africa extends the fossil record of this clade on that continent by as much as 25 million years, and confirms the presence of large-sized owls in Oligocene continental faunas. The new fossil is tentatively referred to the Selenornithinae, a clade of large owls previously restricted to Europe. This new fossil owl was likely similar in size to the extant Eagle Owls of the genus Bubo, and suggests that the niche of large, volant, terrestrial avian predator, although relatively rare throughout avian evolutionary history, may be an ecological role that was more common among extinct owls than previously recognized.

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 The fossil record and macroevolutionary history of the beetles

2015 ◽  
Vol 282 (1805) ◽  
pp. 20150060 ◽  
Author(s):  
Dena M. Smith ◽  
Jonathan D. Marcot
Keyword(s):  
Early Cretaceous ◽  
Fossil Record ◽  
Evolutionary History ◽  
Diversification Rate ◽  
Extinction Rate ◽  
Diverse Group ◽  
Taxonomic Richness ◽  
Lacustrine Deposits ◽  
Family Level ◽  
History Of

Coleoptera (beetles) is the most species-rich metazoan order, with approximately 380 000 species. To understand how they came to be such a diverse group, we compile a database of global fossil beetle occurrences to study their macroevolutionary history. Our database includes 5553 beetle occurrences from 221 fossil localities. Amber and lacustrine deposits preserve most of the beetle diversity and abundance. All four extant suborders are found in the fossil record, with 69% of all beetle families and 63% of extant beetle families preserved. Considerable focus has been placed on beetle diversification overall, however, for much of their evolutionary history it is the clade Polyphaga that is most responsible for their taxonomic richness. Polyphaga had an increase in diversification rate in the Early Cretaceous, but instead of being due to the radiation of the angiosperms, this was probably due to the first occurrences of beetle-bearing amber deposits in the record. Perhaps, most significant is that polyphagan beetles had a family-level extinction rate of zero for most of their evolutionary history, including across the Cretaceous–Palaeogene boundary. Therefore, focusing on the factors that have inhibited beetle extinction, as opposed to solely studying mechanisms that may promote speciation, should be examined as important determinants of their great diversity today.

On the need of providing tooth morphology in descriptions of extant elasmobranch species

Zootaxa ◽  
2018 ◽  
Vol 4461 (1) ◽  
pp. 118 ◽  
Author(s):  
GUILLAUME GUINOT ◽  
SYLVAIN ADNET ◽  
KENSHU SHIMADA ◽  
KENSHU SHIMADA ◽  
CHARLIE J. UNDERWOOD ◽  
...  
Keyword(s):  
Fossil Record ◽  
Evolutionary History ◽  
Lower Jurassic ◽  
Geological Time ◽  
Crown Group ◽  
Large Numbers ◽  
Mineralized Tissues ◽  
Elasmobranch Species ◽  
Cartilaginous Fishes ◽  
The Rich

Elasmobranchii is a clade of chondrichthyans (cartilaginous fishes) that comprises sharks, skates and rays represented today by approximately 1,200 species. Chondrichthyans have a long evolutionary history dating back to the Late Ordovician (ca. 450 million years ago [Mya]) based on isolated dermal denticles (Janvier 1996). Other remains such as articulated skeletons and teeth are known from the Lower Devonian (ca. 410 Mya: Mader 1986; Miller et al. 2003). The fossil record of modern elasmobranchs (Neoselachii) can be traced back to the Early Permian (ca. 290 Mya) and is represented by isolated teeth (Ivanov 2005), with fossils of crown group sharks and rays appearing in Lower Jurassic (ca. 200 Mya) rocks (e.g., Cappetta 2012). Since their appearance in the geological record, elasmobranchs are mainly represented by isolated teeth, whereas articulated skeletons are very rare and restricted to a small number of fossil localities (e.g., Cappetta 2012). The scarcity of skeletal remains in their fossil record is due to their poorly mineralized cartilaginous skeleton that requires special taphonomical conditions to be preserved. Elasmobranch teeth, in contrast, are composed of highly mineralized tissues (hydroxyapatite) that have a strong preservation potential (Shimada 2006). In addition, elasmobranchs replace their teeth continuously over the course of their life span (polyphyodonty) and therefore shed thousands of teeth in their lifetime (Reif et al. 1978; Schnetz et al. 2016) leading to large numbers of potential fossils. These morphologically highly diverse isolated teeth constitute much of the rich fossil record of elasmobranchs, and largely form the basis of our understanding of elasmobranch diversity and evolution through geological time. 

Integrating phylogeny, molecular clocks, and the fossil record in the evolution of coralline algae (Corallinales and Sporolithales, Rhodophyta)

Paleobiology ◽  
2010 ◽  
Vol 36 (4) ◽  
pp. 519-533 ◽  
Author(s):  
Julio Aguirre ◽  
Francisco Perfectti ◽  
Juan C. Braga
Keyword(s):  
Molecular Phylogeny ◽  
Fossil Record ◽  
Evolutionary History ◽  
Coralline Algae ◽  
Molecular Clocks ◽  
Phylogenetic Reconstructions ◽  
Stratigraphic Record ◽  
History Of ◽  
Ideal Group ◽  
18S Rdna Gene

When assessing the timing of branching events in a phylogeny, the most important tools currently recognized are a reliable molecular phylogeny and a continuous, relatively complete fossil record. Coralline algae (Rhodophyta, Corallinales, and Sporolithales) constitute an ideal group for this endeavor because of their excellent fossil record and their consistent phylogenetic reconstructions. We present the evolutionary history of the corallines following a novel, combined approach using their fossil record, molecular phylogeny (based on the 18S rDNA gene sequences of 39 coralline species), and molecular clocks. The order of appearance of the major monophyletic taxa of corallines in the fossil record perfectly matches the sequence of branching events in the phylogeny. We were able to demonstrate the robustness of the node ages in the phylogeny based on molecular clocks by performing an analysis of confidence intervals and maximum temporal ranges of three monophyletic groups of corallines (the families Sporolithaceae and Hapalidiaceae, as well as the subfamily Lithophylloideae). The results demonstrate that their first occurrences are close to their observed appearances, a clear indicator of a very complete stratigraphic record. These chronological data are used to confidently constrain the ages of the remaining branching events in the phylogeny using molecular clocks.

scholarly journals Molecular clocks and the early evolution of metazoan nervous systems

2015 ◽  
Vol 370 (1684) ◽  
pp. 20150046 ◽  
Author(s):  
Gregory A. Wray
Keyword(s):  
Sensory Processing ◽  
Fossil Record ◽  
Sequence Data ◽  
Divergence Times ◽  
Molecular Clocks ◽  
Sense Organs ◽  
Animal Evolution ◽  
Nervous Systems ◽  
Nervous System Evolution ◽  
Fossil Records

The timing of early animal evolution remains poorly resolved, yet remains critical for understanding nervous system evolution. Methods for estimating divergence times from sequence data have improved considerably, providing a more refined understanding of key divergences. The best molecular estimates point to the origin of metazoans and bilaterians tens to hundreds of millions of years earlier than their first appearances in the fossil record. Both the molecular and fossil records are compatible, however, with the possibility of tiny, unskeletonized, low energy budget animals during the Proterozoic that had planktonic, benthic, or meiofaunal lifestyles. Such animals would likely have had relatively simple nervous systems equipped primarily to detect food, avoid inhospitable environments and locate mates. The appearance of the first macropredators during the Cambrian would have changed the selective landscape dramatically, likely driving the evolution of complex sense organs, sophisticated sensory processing systems, and diverse effector systems involved in capturing prey and avoiding predation.

scholarly journals Global Distribution and Evolutionary History of Enterovirus D68, with Emphasis on the 2014 Outbreak in Ontario, Canada

2017 ◽  
Vol 8 ◽  
Author(s):  
Alireza Eshaghi ◽  
Venkata R. Duvvuri ◽  
Sandra Isabel ◽  
Philip Banh ◽  
Aimin Li ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Global Distribution ◽  
History Of ◽  
Enterovirus D68

Anatomical, morphometric, and stratigraphic analyses of theropod biodiversity in the Upper Cretaceous (Campanian) Dinosaur Park Formation

2021 ◽  
pp. 1-15
Author(s):  
Thomas M. Cullen ◽  
Lindsay Zanno ◽  
Derek W. Larson ◽  
Erinn Todd ◽  
Philip J. Currie ◽  
...  
Keyword(s):  
High Resolution ◽  
North America ◽  
Fossil Record ◽  
Upper Cretaceous ◽  
Environmental Changes ◽  
Morphometric Analyses ◽  
Variable Distribution ◽  
Taxic Diversity ◽  
Dinosaur Park Formation ◽  
Broad Scale

The Dinosaur Park Formation (DPF) of Alberta, Canada, has produced one of the most diverse dinosaur faunas, with the record favouring large-bodied taxa, in terms of number and completeness of skeletons. Although small theropods are well documented in the assemblage, taxonomic assessments are frequently based on isolated, fragmentary skeletal elements. Here we reassess DPF theropod biodiversity using morphological comparisons, high-resolution biostratigraphy, and morphometric analyses, with a focus on specimens/taxa originally described from isolated material. In addition to clarifying taxic diversity, we test whether DPF theropods preserve faunal zonation/turnover patterns similar to those previously documented for megaherbivores. Frontal bones referred to a therizinosaur (cf. Erlikosaurus), representing among the only skeletal record of the group from the Campanian–Maastrichtian (83–66 Ma) fossil record of North America, plot most closely to troodontids in morphospace, distinct from non-DPF therizinosaurs, a placement supported by a suite of troodontid anatomical frontal characters. Postcranial material referred to cf. Erlikosaurus in North America is also reviewed and found most similar in morphology to caenagnathids, rather than therizinosaurs. Among troodontids, we document considerable morphospace and biostratigraphic overlap between Stenonychosaurus and the recently described Latenivenatrix, as well as a variable distribution of putatively autapomorphic characters, calling the validity of the latter taxon into question. Biostratigraphically, there are no broad-scale patterns of faunal zonation similar to those previously documented in ornithischians from the DPF, with many theropods ranging throughout much of the formation and overlapping extensively, possibly reflecting a lack of sensitivity to environmental changes, or other cryptic ecological or evolutionary factors.

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