scholarly journals Cretophengodidae, a new Cretaceous beetle family, sheds light on the evolution of bioluminescence

2021 ◽  
Vol 288 (1943) ◽  
pp. 20202730
Author(s):  
Yan-Da Li ◽  
Robin Kundrata ◽  
Erik Tihelka ◽  
Zhenhua Liu ◽  
Diying Huang ◽  
...  
Keyword(s):  
Fossil Record ◽  
Historical Biogeography ◽  
Tree Of Life ◽  
Light Organ ◽  
Defensive Function ◽  
Stem Group

Bioluminescent beetles of the superfamily Elateroidea (fireflies, fire beetles, glow-worms) are the most speciose group of terrestrial light-producing animals. The evolution of bioluminescence in elateroids is associated with unusual morphological modifications, such as soft-bodiedness and neoteny, but the fragmentary nature of the fossil record discloses little about the origin of these adaptations. We report the discovery of a new bioluminescent elateroid beetle family from the mid-Cretaceous of northern Myanmar ( ca 99 Ma), Cretophengodidae fam. nov. Cretophengodes azari gen. et sp. nov. belongs to the bioluminescent lampyroid clade, and would appear to represent a transitional fossil linking the soft-bodied Phengodidae + Rhagophthalmidae clade and hard-bodied elateroids. The fossil male possesses a light organ on the abdomen which presumably served a defensive function, documenting a Cretaceous radiation of bioluminescent beetles coinciding with the diversification of major insectivore groups such as frogs and stem-group birds. The discovery adds a key branch to the elateroid tree of life and sheds light on the evolution of soft-bodiedness and the historical biogeography of elateroid beetles.

scholarly journals Fossil biogeography: a new model to infer dispersal, extinction and sampling from palaeontological data

2016 ◽  
Vol 371 (1691) ◽  
pp. 20150225 ◽  
Author(s):  
Daniele Silvestro ◽  
Alexander Zizka ◽  
Christine D. Bacon ◽  
Borja Cascales-Miñana ◽  
Nicolas Salamin ◽  
...  
Keyword(s):  
North America ◽  
Fossil Record ◽  
Phylogenetic Trees ◽  
Phylogenetic Analyses ◽  
Historical Biogeography ◽  
Extinction Rates ◽  
Climatic Cooling ◽  
Fossil Data ◽  
Incomplete Sampling ◽  
Des Model

Methods in historical biogeography have revolutionized our ability to infer the evolution of ancestral geographical ranges from phylogenies of extant taxa, the rates of dispersals, and biotic connectivity among areas. However, extant taxa are likely to provide limited and potentially biased information about past biogeographic processes, due to extinction, asymmetrical dispersals and variable connectivity among areas. Fossil data hold considerable information about past distribution of lineages, but suffer from largely incomplete sampling. Here we present a new dispersal–extinction–sampling (DES) model, which estimates biogeographic parameters using fossil occurrences instead of phylogenetic trees. The model estimates dispersal and extinction rates while explicitly accounting for the incompleteness of the fossil record. Rates can vary between areas and through time, thus providing the opportunity to assess complex scenarios of biogeographic evolution. We implement the DES model in a Bayesian framework and demonstrate through simulations that it can accurately infer all the relevant parameters. We demonstrate the use of our model by analysing the Cenozoic fossil record of land plants and inferring dispersal and extinction rates across Eurasia and North America. Our results show that biogeographic range evolution is not a time-homogeneous process, as assumed in most phylogenetic analyses, but varies through time and between areas. In our empirical assessment, this is shown by the striking predominance of plant dispersals from Eurasia into North America during the Eocene climatic cooling, followed by a shift in the opposite direction, and finally, a balance in biotic interchange since the middle Miocene. We conclude by discussing the potential of fossil-based analyses to test biogeographic hypotheses and improve phylogenetic methods in historical biogeography.

scholarly journals Flying rocks and flying clocks: disparity in fossil and molecular dates for birds

2014 ◽  
Vol 281 (1788) ◽  
pp. 20140677 ◽  
Author(s):  
Daniel T. Ksepka ◽  
Jessica L. Ware ◽  
Kristin S. Lamm
Keyword(s):  
Analytical Methods ◽  
Fossil Record ◽  
Tree Of Life ◽  
Temporal Information ◽  
Molecular Dating ◽  
Critical Nodes ◽  
Molecular Divergence ◽  
Divergence Dates ◽  
Divergence Estimates ◽  
Age Estimates

Major disparities are recognized between molecular divergence dates and fossil ages for critical nodes in the Tree of Life, but broad patterns and underlying drivers remain elusive. We harvested 458 molecular age estimates for the stem and crown divergences of 67 avian clades to explore empirical patterns between these alternate sources of temporal information. These divergence estimates were, on average, over twice the age of the oldest fossil in these clades. Mitochondrial studies yielded older ages than nuclear studies for the vast majority of clades. Unexpectedly, disparity between molecular estimates and the fossil record was higher for divergences within major clades (crown divergences) than divergences between major clades (stem divergences). Comparisons of dates from studies classed by analytical methods revealed few significant differences. Because true divergence ages can never be known with certainty, our study does not answer the question of whether fossil gaps or molecular dating error account for a greater proportion of observed disparity. However, empirical patterns observed here suggest systemic overestimates for shallow nodes in existing molecular divergence dates for birds. We discuss underlying biases that may drive these patterns.

Rare primitive deuterostomes from the Cambrian (Series 3) of Utah

2015 ◽  
Vol 89 (4) ◽  
pp. 631-636 ◽  
Author(s):  
Simon Conway Morris ◽  
Susan L. Halgedahl ◽  
Paul Selden ◽  
Richard D. Jarrard
Keyword(s):  
New Species ◽  
Fossil Record ◽  
Type Species ◽  
The Body ◽  
New Taxon ◽  
Burgess Shale ◽  
Anterior Section ◽  
Stem Group ◽  
Stratigraphic Range ◽  
New Discovery

AbstractThe fossil record of early deuterostome history largely depends on soft-bodied material that is generally rare and often of controversial status. Banffiids and vetulicystids exemplify these problems. From the Cambrian (Series 3) of Utah, we describe specimens of Banffia episoma n. sp. (from the Spence Shale) and Thylacocercus ignota n. gen. n. sp. (from the Wheeler Formation). The new species of Banffia Walcott, 1911 shows significant differences to the type species (B. constricta Walcott, 1911) from the Cambrian (Series 3, Stage 5) Burgess Shale, notably in possessing a prominent posterior unit but diminished anterior section. Not only does this point to a greater diversity of form among the banffiids, but also B. episoma indicates that the diagnostic median constriction and crossover of either side of the body are unlikely to be the result of taphonomic twisting but are original features. Comparisons extend also to the Cambrian (Series 2) Heteromorphus Luo and Hu in Luo et al., 1999 and, collectively, these observations support an assignment of the banffiids to the vetulicolians. The new taxon T. ignota represents the first discovery of a vetulicystid from beyond China and also significantly extends its stratigraphic range from Series 2 Cambrian into Series 3 Cambrian. Despite overall similarities in bodyplan, T. ignota differs from other vetulicystids in a number of respects, notably the possession of an anterior zone with broad tentacle-like structures. This new discovery is consistent with the vetulicystids representing stem-group ambulacrarians.

scholarly journals The fossil record of early eukaryotic diversification

2004 ◽  
Vol 10 ◽  
pp. 35-50 ◽  
Author(s):  
Susannah M. Porter
Keyword(s):  
Fossil Record ◽  
Main Phase ◽  
Cambrian Explosion ◽  
Evolution Of Sex ◽  
Crown Group ◽  
Long Period ◽  
Stem Group ◽  
Group Evolution ◽  
Domains Of Life ◽  
Ecology And Environment

The Cambrian explosion can be thought of as the culmination of a diversification of eukaryotes that had begun several hundred million years before. Eukaryotes - one of the three domains of life — originated by late Archean time, and probably underwent a long period of stem group evolution during the Paleoproterozoic Era. A suite of taxonomically resolved body fossils and biomarkers, together with estimates of acritarch and compression fossil diversity, suggest that while divergences among major eukaryotic clades or 'super-groups' may have occurred as early as latest Paleoproterozoic through Mesoproterozoic time, the main phase of eukaryotic diversification took place several hundred million years later, during the middle Neoproterozoic Era. Hypotheses for Neoproterozoic diversification must therefore explain why eukaryotic diversification is delayed several hundred million years after the origin of the eukaryotic crown group, and why diversification appears to have occurred independently within several eukaryotic super-groups at the same time. Evolutionary explanations for eukaryotic diversification (the evolution of sex; the acquisition of plastids) fail to account for these patterns, but ecological explanations (the advent of microbial predators) and environmental explanations (changes in ocean chemistry) are both consistent with them. Both ecology and environment may have played a role in triggering or at least fueling Neoproterozoic eukaryotic diversification.

A new genus and species of spoon-winged lacewing from the Cretaceous Crato Formation in Brazil (Neuroptera: Nemopteridae)

2020 ◽  
Vol 3 (4) ◽  
pp. 338-341
Author(s):  
ANDRÉ NEL ◽  
CRISTIAN PELLA
Keyword(s):  
Early Cretaceous ◽  
Fossil Record ◽  
New Genus ◽  
Late Eocene ◽  
New Genus And Species ◽  
Burmese Amber ◽  
Early Oligocene ◽  
Stem Group

The lacewing family Nemopteridae Burmeister, 1839 is very poorly represented in the fossil record with three Early Cretaceous genera of uncertain affinities from the Brazilian Crato Formation, one ‘mid’-Cretaceous representative of the stem group of the Crocinae Navás, 1910 in the Burmese amber, and two Cenozoic nemopterine genera Marquettia Navás, 1913 (late Eocene-early Oligocene) and Paleonemia Claisse et al., 2019 (middle Oligocene). Also two undetermined Nemopterinae are recorded from the late Eocene and the Oligocene (Lu et al., 2019a: Table 1; Claisse et al., 2019).

A Panorpoid (Insecta: Mecoptera) from the Lower Eocene of Patagonia, Argentina

2009 ◽  
Vol 83 (6) ◽  
pp. 994-997 ◽  
Author(s):  
Julián F. Petrulevičius
Keyword(s):  
South America ◽  
Southern Hemisphere ◽  
Lower Cretaceous ◽  
Fossil Record ◽  
Uneven Distribution ◽  
Fossil Insects ◽  
Lower Eocene ◽  
Southern South America ◽  
Stem Group ◽  
Recent Species

The order Mecoptera is represented on all continents, albeit with an uneven distribution. Mecoptera includes about 34 families (Labandeira, 1994, p. 34), only four of them, until now, represented in South America: Permochoristidae Tillyard, 1917 (†) (Pinto, 1972); Bittacidae Handlirsch, 1906 [and stem-group “Neorthophlebinae” (†)] (Petrulevičius, 2001a, 2003, 2007); Nannochoristidae Tillyard, 1917; and Eomeropidae Cockerell, 1909. The two latter families have a present relict distribution in southern South America but without fossil record, obviously an artifact due to few studies of fossil insects in the subcontinent. The diversity of recent Bittacidae is high in South America with respect to other continents. Thirty-five percent of recent genera of Bittacidae come from South America, and 80% of these genera are endemic (extracted from Penny, 1997). Bittacidae is well represented in the fossil record, with species from the Jurassic of Patagonia (Petrulevičius, 2007), Lower Cretaceous of Brazil (Petrulevičius and Martins-Neto, 2001), to the late Paleocene of Argentina (Petrulevičius, 1998, 1999, 2001b, 2003). This contribution reports a specimen belonging to the Panorpoidea, a group with no recent species in South America and very few species in the entire Southern Hemisphere.

scholarly journals The dynamics of stem and crown groups

2019 ◽  
Author(s):  
Graham E. Budd ◽  
Richard P. Mann
Keyword(s):  
Molecular Clock ◽  
Fossil Record ◽  
Null Hypothesis ◽  
Mass Extinctions ◽  
Crown Group ◽  
Stem Group ◽  
Group Members ◽  
Evolutionary Explanations ◽  
Birth Death

ABSTRACTThe fossil record of the origins of major groups is of great interests to many biologists, especially when the fossil record apparently conflicts with timings based on molecular clock estimates. Here we model the diversity of “stem” (basal) and “crown” (modern) members of groups as seen in the fossil record, using a “birth-death model”. Under background conditions, the stem group members must diversify rapidly until the modern crown group emerges, at which point their diversity rapidly collapses, followed shortly by their extinction. Mass extinctions can disturb this pattern to create very diverse stem groups such as the dinosaurs and trilobites. Understanding these null-hypothesis patterns is essential for framing ecological and evolutionary explanations for how major groups originate and subsequently evolve.

scholarly journals Anamorphic development and extended parental care in a 520 million-year-old stem-group euarthropod from China

2018 ◽  
Author(s):  
Dongjing Fu ◽  
Javier Ortega-Hernández ◽  
Allison C. Daley ◽  
Xingliang Zhang ◽  
Degan Shu
Keyword(s):  
Parental Care ◽  
Fossil Record ◽  
Growth Zone ◽  
Posterior Growth Zone ◽  
Stem Group ◽  
History Of ◽  
Sexually Mature ◽  
Chengjiang Lagerstätte ◽  
Extended Parental Care ◽  
Anamorphic Development

AbstractExtended parental care (XPC) is a complex reproductive strategy in which progenitors actively look after their offspring up to – or beyond – the first juvenile stage in order to maximize their fitness. Although the euarthropod fossil record has produced several examples of brood-care, the appearance of XPC within this phylum remains poorly constrained given the scarcity of developmental data for Palaeozoic stem-group representatives that would link juvenile and adult forms in an ontogenetic sequence. Here, we describe the post-embryonic growth of Fuxianhuia protensa from the early Cambrian Chengjiang Lagerstätte, and show parental care in this stem-group euarthropod. We recognize fifteen distinct ontogenetic stages based on the number and shape of the trunk tergites, and their allocation between the morphologically distinct thorax and abdomen. Our data demonstrate anamorphic post-embryonic development in F. protensa, in which tergites were sequentially added from a posterior growth zone. A life assemblage consisting of a sexually mature F. protensa adult alongside four ontogenetically coeval juveniles, constitutes the oldest occurrence of XPC in the panarthropod fossil record. These findings provide the most phylogenetically basal evidence of anamorphosis in the evolutionary history of total-group Euarthropoda, and reveal a complex post-embryonic reproductive ecology for its early representatives.

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