scholarly journals Late Cretaceous domatia reveal the antiquity of plant–mite mutualisms in flowering plants

2019 ◽  
Vol 15 (11) ◽  
pp. 20190657 ◽  
Author(s):  
S. Augusta Maccracken ◽  
Ian M. Miller ◽  
Conrad C. Labandeira
Keyword(s):  
Late Cretaceous ◽  
Fossil Record ◽  
Evolutionary History ◽  
Upper Cretaceous ◽  
Flowering Plants ◽  
Predaceous Mites ◽  
First Occurrence ◽  
History Of ◽  
Living Species ◽  
Cenozoic Era

Mite houses, or acarodomatia, are found on the leaves of over 2000 living species of flowering plants today. These structures facilitate tri-trophic interactions between the host plant, its fungi or herbivore adversaries, and fungivorous or predaceous mites by providing shelter for the mite consumers. Previously, the oldest acarodomatia were described on a Cenozoic Era fossil leaf dating to 49 Myr in age. Here, we report the first occurrence of Mesozoic Era acarodomatia in the fossil record from leaves discovered in the Upper Cretaceous Kaiparowits Formation (76.6–74.5 Ma) in southern UT, USA. This discovery extends the origin of acarodomatia by greater than 25 Myr, and the antiquity of this plant–mite mutualism provides important constraints for the evolutionary history of acarodomatia on angiosperms.

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 Coordinated shifts to non-planktotrophic development in spatangoid echinoids during the Late Cretaceous

2009 ◽  
Vol 5 (5) ◽  
pp. 647-650 ◽  
Author(s):  
John A. Cunningham ◽  
Charlotte H. Jeffery Abt
Keyword(s):  
Larval Development ◽  
Late Cretaceous ◽  
Fossil Record ◽  
Evolutionary History ◽  
Sea Urchins ◽  
Geological History ◽  
Extrinsic Factors ◽  
Genus Level ◽  
History Of ◽  
Widespread Interest

Despite widespread interest in the interplay between evolutionary and developmental processes, we still know relatively little about the evolutionary history of larval development. Many clades exhibit multiple shifts from planktotrophic (feeding) to non-planktotrophic (non-feeding) larval development. An important question is whether these switches are scattered randomly through geological history or are concentrated in particular intervals of time. This issue is addressed using the Cretaceous spatangoid sea urchins, which are unusual in that larval strategy can be determined unambiguously from abundantly fossilized adult tests. Using a genus-level phylogeny, we identify five clades of non-planktotrophic taxa, each of which first appears in the fossil record in the Campanian or Maastrichtian (the final two Cretaceous stages). No examples of non-planktotrophy have been identified in any of the earlier stages of the Cretaceous. This strongly suggests that shifts to non-planktotrophic development are clustered in certain episodes of geological history, and this, in turn, implies that extrinsic factors operating at these times are responsible for driving shifts in developmental strategy.

First occurrence of Maiasaura (Dinosauria, Hadrosauridae) from the Upper Cretaceous Oldman Formation of southern Alberta, Canada

2020 ◽  
pp. 1-11
Author(s):  
Bradley D. McFeeters ◽  
David C. Evans ◽  
Michael J. Ryan ◽  
Hillary C. Maddin
Keyword(s):  
Posterior Margin ◽  
Evolutionary History ◽  
Upper Cretaceous ◽  
Dorsal Surface ◽  
Adult Size ◽  
Southern Alberta ◽  
First Occurrence ◽  
History Of ◽  
Phylogenetic Divergence ◽  
The Relationship

We describe a new partial skull with braincase of a maiasaurin hadrosaurid from the Milk River Ridge Reservoir near Warner, southern Alberta, as the first diagnostic occurrence of Maiasaura in Canada. This material was collected in the Oldman Formation, at approximately the same stratigraphic level as a nearby bonebed of the ceratopsid Coronosaurus brinkmani. The assignment of this specimen to Maiasaura, rather than to Brachylophosaurus, is supported by the narrow and acute posterior margin of the external naris, the relationship between the postorbital and squamosal in the supratemporal bar, and the morphology of the frontals, which are greatly thickened and elevated anteriorly, with the dorsal surface not completely covered by the nasofrontal contact at adult size. The occurrence of both Maiasaura and Brachylophosaurus in approximately similar-aged deposits of the Comrey Sandstone zone in southern Alberta provides support for some cladogenesis in the evolutionary history of Maiasaurini. Geographically, the more western distribution of Maiasaura localities with respect to all Brachylophosaurus localities is consistent with the hypothesis that a preference for more inland versus seaway-adjacent habitats may have influenced the phylogenetic divergence of these taxa.

Missing Links in the History of Life

2002 ◽  
Vol 11 ◽  
pp. 97-118
Author(s):  
Charles R. Marshall
Keyword(s):  
Evolutionary Theory ◽  
Fossil Record ◽  
Theory Of Evolution ◽  
History Of ◽  
Living Species

Ever since Darwin proposed his theory of evolution (or more correctly, theories; see Mayr, 1991) it has been assumed that intermediates now extinct once existed between living species. For some, the hunt for these so-called missing links in the fossil record became an obsession, a search for evidence thought needed to establish the veracity of evolutionary theory. Few modern paleontologists, however, search explicitly for ancestors in the fossil record because we now know that fossils can be used to chart the order of evolution regardless of whether they are directly ancestral either to extinct organisms or to those living today.

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 A comparative atlas of the skull osteology of European lizards (Reptilia: Squamata)

2019 ◽  
Vol 187 (3) ◽  
pp. 829-928 ◽  
Author(s):  
Andrea Villa ◽  
Massimo Delfino
Keyword(s):  
Fossil Record ◽  
Evolutionary History ◽  
European Species ◽  
History Of ◽  
Diagnostic Key ◽  
Single Bone ◽  
Fossil Lizards ◽  
Bone Remains ◽  
Comparative Osteology ◽  
Broad Scale

Abstract The fossil record provides evidence of a long evolutionary history of European lizards. Since fossil lizards are regularly represented by bone remains, the knowledge of the origins of extant taxa and their distribution in time and space is hindered by the fact that their comparative osteology is not yet completely and adequately known. In spite of a rising interest in this topic since the end of the 20th century, a gap in our knowledge is still evident. We here report the first broad-scale comparative osteological analysis of the skulls of extant European lizards, highlighting significant differences that can be used in identification. This comparative study, including as many European species as possible, leads to the creation of a detailed diagnostic key for each single bone. Also, our data significantly improve the recognizability of extant European non-snake squamates, with 54% of the current diversity to be recognized based on the new results contra the previously estimated 31%. This recognizability is expected to further increase in the future, with new studies focusing on species that are either missing or poorly represented here, or applying promising advanced methodologies.

Missing Links in the History of Life

1999 ◽  
Vol 9 ◽  
pp. 119-144
Author(s):  
Charles R. Marshall
Keyword(s):  
Evolutionary Theory ◽  
Fossil Record ◽  
Theory Of Evolution ◽  
History Of ◽  
Living Species

Ever since Darwin proposed his theory of evolution (or more correctly, theories; see Mayr, 1991) it has been assumed that intermediates now extinct once existed between living species. For some, the hunt for these so-called missing links in the fossil record became an obsession, a search for evidence thought needed to establish the veracity of evolutionary theory. Few modern paleontologists, however, search explicitly for ancestors in the fossil record because we now know that fossils can be used to chart the order of evolution regardless of whether they are directly ancestral either to extinct organisms or those living today.

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