scholarly journals The fossil Osmundales (Royal Ferns)—a phylogenetic network analysis, revised taxonomy, and evolutionary classification of anatomically preserved trunks and rhizomes

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3433 ◽  
Author(s):  
Benjamin Bomfleur ◽  
Guido W. Grimm ◽  
Stephen McLoughlin
Keyword(s):  
Fossil Record ◽  
Phylogenetic Network ◽  
Structural Features ◽  
Fossil Species ◽  
Extant Species ◽  
Taxonomic Concept ◽  
History Of ◽  
Character Matrix ◽  
Source Of Information

The Osmundales (Royal Fern order) originated in the late Paleozoic and is the most ancient surviving lineage of leptosporangiate ferns. In contrast to its low diversity today (less than 20 species in six genera), it has the richest fossil record of any extant group of ferns. The structurally preserved trunks and rhizomes alone are referable to more than 100 fossil species that are classified in up to 20 genera, four subfamilies, and two families. This diverse fossil record constitutes an exceptional source of information on the evolutionary history of the group from the Permian to the present. However, inconsistent terminology, varying formats of description, and the general lack of a uniform taxonomic concept renders this wealth of information poorly accessible. To this end, we provide a comprehensive review of the diversity of structural features of osmundalean axes under a standardized, descriptive terminology. A novel morphological character matrix with 45 anatomical characters scored for 15 extant species and for 114 fossil operational units (species or specimens) is analysed using networks in order to establish systematic relationships among fossil and extant Osmundales rooted in axis anatomy. The results lead us to propose an evolutionary classification for fossil Osmundales and a revised, standardized taxonomy for all taxa down to the rank of (sub)genus. We introduce several nomenclatural novelties: (1) a new subfamily Itopsidemoideae (Guaireaceae) is established to containItopsidema,Donwelliacaulis, andTiania; (2) the thamnopteroid generaZalesskya,Iegosigopteris, andPetcheropterisare all considered synonymous withThamnopteris; (3) 12 species ofMillerocaulisandAshicaulisare assigned to modern genera (tribe Osmundeae); (4) the hitherto enigmaticAurealcaulisis identified as an extinct subgenus ofPlenasium; and (5) the poorly knownOsmundites tuhajkulensisis assigned toMillerocaulis. In addition, we considerMillerocaulis stipabonettioruma possible member ofPalaeosmundaandMillerocaulis estipularisas probably constituting the earliest representative of the (Todea-)Leptopterislineage (subtribe Todeinae) of modern Osmundoideae.

A new fossil species of the Australian endemic genus Peradenia Naumann & Masner (Hymenoptera: Proctotrupoidea, Peradeniidae) from Baltic Amber

2001 ◽  
Vol 32 (2) ◽  
pp. 191-194 ◽  
Author(s):  
Jens-Wilhelm Janzen ◽  
Norman F. Johnson ◽  
Luciana Musetti
Keyword(s):  
Baltic Amber ◽  
Australian Capital Territory ◽  
Fossil Species ◽  
Southeastern Australia ◽  
Extant Species ◽  
The Family ◽  
The Status ◽  
Subfamily Classification ◽  
A New Species

AbstractThe family Peradeniidae (Hymenoptera: Proctotrupoidea) is represented by two rare extant species from southeastern Australia (Australian Capital Territory, Victoria, Tasmania). A new species, Peradenia galerita sp. n., is described from Eocene Baltic amber. The fossil species is very similar to the living Perndenia, but has the short metasomatic petiole typical of most Proctotrupoidea. The subfamily classification of Heloridae proposed by Rasnitsyn and the status of Peradeniidae are briefly reviewed. The subfamily Mesohelorinae Rasnitsyn, 1990 is a junior synonym of Protohelorinae Rasnitsyn, 1980 (syn. n.).

scholarly journals The fossil history of pseudoscorpions (Arachnida: Pseudoscorpiones)

Fossil Record ◽  
2017 ◽  
Vol 20 (2) ◽  
pp. 215-238 ◽  
Author(s):  
Danilo Harms ◽  
Jason A. Dunlop
Keyword(s):  
Fossil Record ◽  
Baltic Amber ◽  
Tree Bark ◽  
Valid Species ◽  
Morphological Reconstruction ◽  
Morphological Stasis ◽  
History Of ◽  
Extinction Events ◽  
Phylogenetic Affinities

Abstract. Pseudoscorpions, given their resemblance to scorpions, have attracted human attention since the time of Aristotle, although they are much smaller and lack the sting and elongated tail. These arachnids have a long evolutionary history but their origins and phylogenetic affinities are still being debated. Here, we summarise their fossil record based on a comprehensive review of the literature and data contained in other sources. Pseudoscorpions are one of the oldest colonisers of the land, with fossils known since the Middle Devonian (ca. 390 Ma). The only arachnid orders with an older fossil record are scorpions, harvestmen and acariform mites, plus two extinct groups. Pseudoscorpions do not fossilise easily, and records from the Mesozoic and Cenozoic consist almost exclusively of amber inclusions. Most Mesozoic fossils come from Archingeay and Burmese ambers (Late Cretaceous) and those from the Cenozoic are primarily from Eocene Baltic amber, although additional fossils from, for example, Miocene Dominican and Mexican ambers, are known. Overall, 16 of the 26 families of living pseudoscorpions have been documented from fossils and 49 currently valid species are recognised in the literature. Pseudoscorpions represent a case of morphological stasis and even the Devonian fossils look rather modern. Indeed, most amber fossils are comparable to Recent groups despite a major gap in the fossil record of almost 250 Myr. Baltic amber inclusions indicate palaeofauna inhabiting much warmer climates than today and point to climatic shifts in central Europe since the Eocene. They also indicate that some groups (e.g. Feaellidae and Pseudogarypidae) had much wider Eocene distributions. Their present-day occurrence is relictual and highlights past extinction events. Faunas from younger tropical amber deposits (e.g. Dominican and Mexican amber) are comparable to Recent ones. Generally, there is a strong bias in the amber record towards groups that live under tree bark, whereas those from litter habitats are underrepresented. We also discuss challenges in interpreting fossils: their cryptic morphology warranting novel techniques of morphological reconstruction, the massive gap in the fossil record between the Palaeozoic and Mesozoic, and problems with the classification of (historically) old amber material. Finally, we discuss aspects of the palaeoecology and biology of the fossils compared with the Recent fauna, such as phoresy.

The fossil record of Ceratophrys Wied-Neuwied (Anura: Ceratophryidae): a revision and update of fossil South American horned frogs

Zootaxa ◽  
2019 ◽  
Vol 4658 (1) ◽  
pp. 37-68
Author(s):  
LAURA NICOLI
Keyword(s):  
Fossil Record ◽  
South American ◽  
Unique Combination ◽  
Fossil Species ◽  
Environmental Tolerance ◽  
Pampean Region ◽  
Fossil Material ◽  
Extant Species ◽  
Present Distribution ◽  
Living Species

Ceratophrys is the most diverse and widely distributed genus of Ceratophryidae, the clade of South American horned frogs. Numerous anuran fossil remains, including several fossil species, have been assigned to this genus. However, this seemingly extensive fossil record is problematic because several of the fossils are not properly identified and most of the taxonomic assignations are not justified. The present study traces all the fossil material attributed to Ceratophrys, clarifying, when possible, institutional allocations. Each of the remains was examined and its taxonomic assignation revisited, based on the morphology and possible synapomorphies of the genus, including its living species. Numerous fossils were properly identified and assigned with certainty to Ceratophrys. Only one fossil species, Ceratophrys ameghinorum, is considered valid. This information, along with recently reported evidence of fossil Ceratophrys, is briefly summarized to serve as a practical reference for the entire known fossil record of the genus. The fossil record is not especially informative about the evolution or distribution pattern of Ceratophrys, because most of the remains are relatively young (post-Miocene), collected within the present distribution of the genus, and morphologically consistent with that of the extant species. However, some useful information has emerged. The presence of Ceratophrys is well documented since the Neogene in the Pampean Region of South America. The single valid fossil species, Ceratophrys ameghinorum, possesses a unique combination of characters that reflects a mixture of characters observed in different clades of the genus; thus, resolution of its phylogentic position will inform our understanding of the evolution of the genus. The paleoenvironmental significance of some Ceratophrys fossils is also discussed, addressing the wide, but incompletely known current distribution and environmental tolerance of the genus.

Atypical short elytra in Cretaceous short-winged flower beetles (Coleoptera: Kateretidae)

2019 ◽  
Vol 2 (5) ◽  
pp. 505-514 ◽  
Author(s):  
DAVID PERIS ◽  
JOSEF JELÍNEK
Keyword(s):  
Fossil Record ◽  
Ancestral State ◽  
Fossil Species ◽  
Extant Species ◽  
The Family

Although the family Kateretidae has fewer than 100 described extant species, its fossil record is growing. The description given here of Electrumeretes birmanicus gen. et sp. nov. and Polliniretes penalveri gen. et sp. nov. brings the number of fossil species in Kateretidae up to nine. Eight of the fossil species have been described from amber deposits and six are from the Cretaceous. All the Cretaceous fossil species and one from the Eocene share atypically short elytra and three dorsally exposed abdominal tergites, whereas in Recent relatives, even though they have shortened elytra, only the pygidium and a part of the preceding one or two abdominal tergites are exposed. It is suggested that shortened elytra (brachelytry) represents an ancestral state and that elytra may have become secondary longer in extant relatives.

scholarly journals The evolution of methods for establishing evolutionary timescales

2016 ◽  
Vol 371 (1699) ◽  
pp. 20160020 ◽  
Author(s):  
Philip C. J. Donoghue ◽  
Ziheng Yang
Keyword(s):  
Fossil Record ◽  
Environmental Influence ◽  
Molecular Dating ◽  
Divergence Times ◽  
Fossil Species ◽  
Time Estimates ◽  
Fossil Evidence ◽  
Probability Densities ◽  
History Of ◽  
Lineage Divergence

The fossil record is well known to be incomplete. Read literally, it provides a distorted view of the history of species divergence and extinction, because different species have different propensities to fossilize, the amount of rock fluctuates over geological timescales, as does the nature of the environments that it preserves. Even so, patterns in the fossil evidence allow us to assess the incompleteness of the fossil record. While the molecular clock can be used to extend the time estimates from fossil species to lineages not represented in the fossil record, fossils are the only source of information concerning absolute (geological) times in molecular dating analysis. We review different ways of incorporating fossil evidence in modern clock dating analyses, including node-calibrations where lineage divergence times are constrained using probability densities and tip-calibrations where fossil species at the tips of the tree are assigned dates from dated rock strata. While node-calibrations are often constructed by a crude assessment of the fossil evidence and thus involves arbitrariness, tip-calibrations may be too sensitive to the prior on divergence times or the branching process and influenced unduly affected by well-known problems of morphological character evolution, such as environmental influence on morphological phenotypes, correlation among traits, and convergent evolution in disparate species. We discuss the utility of time information from fossils in phylogeny estimation and the search for ancestors in the fossil record. This article is part of the themed issue ‘Dating species divergences using rocks and clocks’.

LA CLASSIFICAZIONE DEGLI STRUMENTI SCIENTIFICI

Nuncius ◽  
1989 ◽  
Vol 4 (1) ◽  
pp. 87-92
Author(s):  
SALVO D'AGOSTINO
Keyword(s):  
Nineteenth Century ◽  
Information Theory ◽  
Structural Features ◽  
Classification Criteria ◽  
Scientific Instruments ◽  
History Of ◽  
Per Se

Abstract<title> SUMMARY </title>Some guiding ideas in the classification of historical scientific instruments are presented, with the aim of specifying usefull selectioncriteria for the exhibition in a scientific museum and historiography for the historian of physics. Classification criteria should be founded on the examination of structural features which belong to the instrument per se and to the modes in which it has been used in meaningful experiments. Examples are given in the history of some nineteenth century Electrometers. Some tools for a meaningful historiography of instruments are indicated in Information Theory.

The morphology and relationships of Equisetum fluviatoides sp.nov. from the Paleocene Ravenscrag Formation of Saskatchewan, Canada

1989 ◽  
Vol 67 (10) ◽  
pp. 2937-2943 ◽  
Author(s):  
E. E. McIver ◽  
J. F. Basinger
Keyword(s):  
Fossil Record ◽  
Evolutionary History ◽  
Central Cavity ◽  
Fossil Species ◽  
Vegetative Organs ◽  
Early Tertiary ◽  
History Of ◽  
Internodal Lengths

Vegetative and associated fertile remains of Equisetum have been recovered from early Tertiary sediments of the Ravenscrag Formation, Saskatchewan, Canada. The morphology of both reproductive and vegetative organs of this fossil species is remarkably similar to that of extant Equisetum fluviatile, the swamp horsetail. Aerial axes of the fossil are 3.0–19.0 mm in diameter, with internodal lengths of up to 30.0 mm. The stems are hollow and the central cavity is large. Branches, apparently simple, are borne in whorls at the nodes. Leaf collars at the nodes are up to 23.0 mm long, longer than broad, with leaves fused in the lower four-fifths of the collar. The leaf apices are long attenuate. Cones are up to 14.0 mm long, bearing peltate, six-sided sporangiophores in whorls of five. The fossil record suggests stasigenesis in the evolutionary history of some members of the genus Equisetum since the beginning of the Tertiary, and perhaps longer.

Recognizing the species of Thuja (Cupressaceae) based on their cone and foliage morphology

Phytotaxa ◽  
2015 ◽  
Vol 219 (2) ◽  
pp. 101 ◽  
Author(s):  
Bin Sun ◽  
Yi-Ming Cui ◽  
Hai-Feng Wang ◽  
David Kay Ferguson ◽  
Qiao-Ping Xiang ◽  
...  
Keyword(s):  
North America ◽  
East Asia ◽  
Evolutionary History ◽  
Morphological Characters ◽  
Species Level ◽  
Fossil Species ◽  
Extant Species ◽  
History Of

Thuja, with 5 extant species, exhibiting a disjunctive distribution between East Asia (3 species) and North America (2 species), was investigated with respect to the morphological characters of foliage and cones by LM and SEM. Here we provide 2 keys to all 5 species of Thuja based on the cones and foliage respectively, which not  only can be used for identifying extant Thuja at the species level, but also have a great potential for recognizing and/or linking the fossil species to living ones, and further tracing the evolutionary history of the genus.

A fossil water measurer from the mid-Cretaceous Burmese amber (Hemiptera: Gerromorpha: Hydrometridae)

2001 ◽  
Vol 32 (4) ◽  
pp. 381-392 ◽  
Author(s):  
Nils Møller Andersen ◽  
David Grimaldi
Keyword(s):  
Evolutionary History ◽  
Wing Venation ◽  
Fossil Species ◽  
Burmese Amber ◽  
Extant Species ◽  
Close Relationship ◽  
History Of

AbstractSemiaquatic bugs (Hemiptera: Gerromorpha) comprise about 1,800 extant species classified in eight families. So far, 38 fossil species belonging to six families have been described or recorded, most of Cenozoic age. Knowledge about the evolutionary history of the major groups of Gerromorpha is seriously hampered by the scarcity of well-preserved Mesozoic fossils, especially from the Cretaceous. The present paper reports on a well-preserved semiaquatic bug from amber collected in the northern part of Myanmar (Burma). The source of this fossiliferous amber was previously considered to be Eocene in age, but recent evidence indicates that it originated in the Middle Cretaceous (Turonian-Cenomanian), or 100-90 Ma. The fossil species is described as Carinametra burmensis gen. et sp. n. The presence of three pairs of cephalic trichobothria, a prolonged head, long slender antennae and legs, reduced wing venation, etc., places the fossil in the gerromorphan family Hydrometridae or water measurers. Other characters suggest a close relationship with the two extant genera of the most basal of the hydrometrid subfamilies, Heterocleptinae. We present and discuss the available evidence used in the dating of Burmese amber. Finally, we discuss the phylogenetic, paleobiological, and biogeographic significance of the new fossil.

On the probability of ancestors in the fossil record

Paleobiology ◽  
1996 ◽  
Vol 22 (2) ◽  
pp. 141-151 ◽  
Author(s):  
Mike Foote
Keyword(s):  
Fossil Record ◽  
Marine Invertebrates ◽  
Fossil Species ◽  
Direct Descendant ◽  
Extant Species ◽  
Homogeneous Models ◽  
Temporal And Spatial

Three homogeneous models of species origination and extinction are used to assess the probability that ancestor-descendant pairs are preserved in the fossil record. In the model of cladogenetic budding, a species can persist after it branches and can therefore have multiple direct descendants. In the bifurcation model, a species branches to give rise to two distinct direct descendants, itself terminating in the process. In the model of phyletic transformation, a species gives rise to a single direct descendant without branching, itself terminating in the process. Assuming homogeneous preservation, even under pessimistic assumptions regarding the completeness of the fossil record, the probability of finding fossil ancestor-descendant pairs is not negligible. Even if all species of Phanerozoic marine invertebrates in the paleontologically important taxa had the same probability of preservation, on the order of 1%-10% or more of the known fossil species would be directly ancestral to other known fossil species. However, this is likely to be an underestimate, since the probability of finding ancestor-descendant pairs is enhanced by taxonomic, temporal, and spatial heterogeneities in preservation probability. Moreover, indirect genealogical relationships substantially increase the probability of finding ancestor-descendant pairs. The model of budding, the only one in which an ancestor can persist after a branching event, predicts that half or more of extant species have ancestors that are also extant. Thus, the question of how to recognize ancestor-descendant pairs must be carefully considered.

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