Using experimental decay of modern forms to reconstruct the early evolution and morphology of fossil enteropneusts

Paleobiology ◽  
2015 ◽  
Vol 41 (3) ◽  
pp. 460-478 ◽  
Author(s):  
Karma Nanglu ◽  
Jean-Bernard Caron ◽  
Christopher B. Cameron
Keyword(s):  
Fossil Record ◽  
Morphological Characters ◽  
Early Diagenesis ◽  
Body Plan ◽  
Morphological Features ◽  
Laboratory Setting ◽  
Burgess Shale ◽  
Comprehensive Understanding ◽  
Fossil Preservation ◽  
Experimental Decay

AbstractDecay experiments are becoming a more widespread tool in evaluating the fidelity of the fossil record. Character interpretations of fossil specimens stand to benefit from an understanding of how decay can result in changes in morphology and, potentially, total character loss. We performed a decay experiment for the Class Enteropneusta to test the validity of anatomical interpretations of the Burgess Shale enteropneust Spartobranchus tenuis and to determine how the preservation of morphological features compares with the sequence of character decay in extant analogues. We used three species of enteropneust (Saccoglossus pusillus, Harrimania planktophilus, and Balanoglossus occidentalis) representing the two major families of Enteropneusta. Comparisons between decay sequences suggest that morphological characters decay in a consistent and predictable manner within Enteropneusta, and do not support the hypothesis of stemward slippage. The gill bars and nuchal skeleton were the most decay resistant, whereas the gill pores and pre-oral ciliary organ were unequivocally the most decay prone. Decay patterns support the identification of the nuchal skeleton, gill bars, esophageal organ, trunk, and proboscis in Spartobranchus tenuis and corroborate a harrimaniid affinity. Bias due to the taphonomic loss of taxonomically informative characters is unlikely. The morphologically simple harrimaniid body plan can be seen, therefore, to be plesiomorphic within the enteropneusts. Discrepancies between the sequence of decay in a laboratory setting and fossil preservation also exist. These discrepancies are highlighted not to discredit the use of modern decay studies but rather to underline their non-actualistic nature. Paleoenvironmental variables besides decay, such as the timeframe between death and early diagenesis as well as postmortem transport, are discussed relative to decay data. These experiments reinforce the strength of a comprehensive understanding of decay sequences as a benchmark against which to describe fossil taxa and understand the conditions leading to fossilization.

A large new species of Rhinella (Anura: Bufonidae) from Cerrado of Brazil

Zootaxa ◽  
2007 ◽  
Vol 1627 (1) ◽  
pp. 23-39 ◽  
Author(s):  
NATAN M. MACIEL ◽  
REUBER A. BRANDÃO ◽  
LEANDRO A. CAMPOS ◽  
ANTONIO SEBBEN
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Morphological Characters ◽  
Morphological Features ◽  
Advertisement Call ◽  
Sexually Dimorphic ◽  
Rhinella Marina ◽  
Large Size ◽  
Morphometric Feature ◽  
Distrito Federal

A new toad, Rhinella cerradensis, is described, including its tadpole and the advertisement call. The new species occupies Cerrado habitats in the Brazilian states of Piauí, Bahia, Goiás, Minas Gerais, and Distrito Federal. The species is characterized by its large size; absence of tibial glands; well developed cranial crests; short hands; sexually dimorphic coloration; and by the absence of a spiracle tube of the tadpole. The new species is included in the Rhinella marina group by the presence of a jagged suture formed by the articulation between the pterygoid medial ramus and the parasphenoid alae, as well as other shared morphological features. Morphological characters and statistical analyses inferred by morphometric feature suggest the existence of two subgroups of species within R. marina group. However, taxonomic rearrangements are not made here and await phylogenetic analysis.

Dinosaur Macroevolution and Macroecology

2018 ◽  
Vol 49 (1) ◽  
pp. 379-408 ◽  
Author(s):  
Roger B.J. Benson
Keyword(s):  
Life History ◽  
Body Size ◽  
Reproductive Biology ◽  
Fossil Record ◽  
Structural Diversity ◽  
Body Plan ◽  
Adaptive Landscape ◽  
Species Diversification ◽  
Size Evolution ◽  
Body Size Evolution

Dinosaurs were large-bodied land animals of the Mesozoic that gave rise to birds. They played a fundamental role in structuring Jurassic–Cretaceous ecosystems and had physiology, growth, and reproductive biology unlike those of extant animals. These features have made them targets of theoretical macroecology. Dinosaurs achieved substantial structural diversity, and their fossil record documents the evolutionary assembly of the avian body plan. Phylogeny-based research has allowed new insights into dinosaur macroevolution, including the adaptive landscape of their body size evolution, patterns of species diversification, and the origins of birds and bird-like traits. Nevertheless, much remains unknown due to incompleteness of the fossil record at both local and global scales. This presents major challenges at the frontier of paleobiological research regarding tests of macroecological hypotheses and the effects of dinosaur biology, ecology, and life history on their macroevolution.

Morphogenetic features of garnets from Dyukunakh placer (Yakutian diamondiferous province)

2021 ◽  
pp. 106-112
Author(s):  
Elvira Vlasova ◽  
Aleksandr Khmelkov
Keyword(s):  
Morphological Characters ◽  
Morphological Features ◽  
Primary Sources ◽  
Residual Soil ◽  
Coastal Marine ◽  
Upper Paleozoic ◽  
Morphogenetic Analysis

Morphological features of garnets from the Upper Paleozoic Dyukunakh placer were studied and the conditions of their morphogenesis were interpreted. As a result of the morphogenetic analysis, it was found that garnets have evolved in exogenous conditions, including extreme wear in coastal marine conditions and repeated redeposition. In addition, garnets underwent significant hypergene corrosion in the residual soil and subsequent dissolution under metasomatic conditions. As a result of such exogenous evolution, no trace of their primary morphological characters associated with the deep stage of morphogenesis remained on garnets. For this reason, it is impossible to quantify the degree of primary sources removal.

A Study of Correlation between Morphology and Evolution of Euphorbiaceae s.l. using Taxonomic Congruence and Total Evidence

2021 ◽  
Vol 9 (1) ◽  
pp. 49-55
Author(s):  
Vanlal hruaia ◽  
◽  
Lal rinmuana ◽  
J Lalbiaknunga ◽  
Laldinfeli Ralte
Keyword(s):  
Phylogenetic Tree ◽  
Evolutionary Relationship ◽  
Cladistic Analysis ◽  
Morphological Characters ◽  
Flowering Plants ◽  
Morphological Features ◽  
Total Evidence ◽  
Pictorial Representation ◽  
Phenetic Analysis ◽  
Morphological Relationship

Euphorbiaceae is one of the largest family of flowering plants, in our study different species were collected from different localities of Mizoram, the collected specimens were studied and their morphological features noted. 34 genera of Euphorbiaceae s.l were used in the study. Cladistic analysis was performed in Mesquite software and Phenetic analysis was done in NTsys software. Both analyses produce a pictorial representation in a form of a tree; cladistic analysis produce phylogenetic tree (evolutionary relationship) while phenetic analysis produce phenogram (morphological relationship). The results of the aforementioned analyses were further analysed by total evidence technique and taxonomic congruence, a phylogenetic software PAUP is used for this purpose. The resultant trees were very different and comparison was done to find correlation between evolution and morphological characters. The research finds various correlation among characters like the number of locule in ovule, phyllanthoid branching and support the inclusion of genus like Breynia, Sauropus into Phyllanthus.

scholarly journals Otomorphs (= otocephalans or ostarioclupeomorphs) revisited

2018 ◽  
Vol 16 (3) ◽  
Author(s):  
Gloria Arratia
Keyword(s):  
Fossil Record ◽  
Morphological Character ◽  
Neotropical Region ◽  
Morphological Features ◽  
Heterogeneous Group ◽  
Vertebral Centra ◽  
Molecular Studies ◽  
Gas Bladder ◽  
Parietal Bones ◽  
Freshwater Environments

ABSTRACT A morphological revision is presented here on the cohort Otomorpha, a clade currently interpreted as the most primitive among the large supercohort Clupeocephala. Otomorpha is a morphologically heterogeneous group represented by clupei forms , alepocephaliforms, and ostariophysans (gonorynchiforms, cypriniforms, characiforms, siluriforms, and gymnoti forms) that inhabit various marine and freshwater environments worldwide. Otomorphs have a long (ca. 145 Ma) and diverse fossil record. They are the largest fish teleostean clade worldwide, as well as the largest of the Neotropical Region. While molecular studies strongly confirm the monophyly of Otomorpha, most potential morphological synapomorphies of the group become homoplastic largely due to the peculiar morphological character states (either losses or transformations) present in alepocephaliforms. The fusion of haemal arches with their respective vertebral centra anterior to preural centrum 2 stands as an unambiguous synapomorphy of the clade. The ankylosis or fusion of the extrascapular and parietal bones, and silvery areas associated with the gas bladder are also interpreted as synapomorphies, although they are homoplastic characters mainly due to secondary losses or further transformations of the morphological features in the alepocephaliforms.

A new fossil species of the genus Limodromus Motschulsky, 1850 (Coleoptera: Carabidae: Platynini) from Baltic amber with remarks on its death process

2018 ◽  
Vol 49 (4) ◽  
pp. 399-408
Author(s):  
Sara Gamboa ◽  
Vicente M. Ortuño
Keyword(s):  
New Species ◽  
Fossil Record ◽  
Species Group ◽  
Morphological Features ◽  
Baltic Amber ◽  
Sister Taxon ◽  
Death Process ◽  
Fossil Species

Limodromus emetikos sp. n. (Coleoptera: Carabidae) is described and illustrated from Baltic amber (Eocene). Based on its morphological features, the new species is considered a sister taxon of the extant Holarctic assimilis species group. Furthermore, the specimen described here could represent a case of stress-triggered regurgitation, which would represent the first fossil record of such a process in beetles.

scholarly journals First Report of a Phytopythium litorale Species Causing Crown and Root Rot on Rhododendron pulchrum in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Yaxing Li ◽  
Yangfan Feng ◽  
Cuiping Wu ◽  
Junxin Xue ◽  
Binbin Jiao ◽  
...  
Keyword(s):  
Root Rot ◽  
Morphological Characters ◽  
Morphological Features ◽  
Crown Rot ◽  
Sterile Water ◽  
First Report ◽  
Inoculation Method ◽  
Platanus Orientalis ◽  
Crown And Root Rot ◽  
Root Tissues

During a survey of pathogenic oomycetes in Nanjing, China from June 2019 to October 2020, at least ten adjacent Rhododendron pulchrum plants at a Jiangjun Mountain scenic spot showed symptoms of blight, and crown and root discoloration . Symptomatic root tissues collected from three 6-year-old plants were rinsed with water, cut into 10-mm pieces, surface sterilized with 70% ethanol for 1 min, and plated onto 10% clarified V8 PARP agar (cV8A-PARP) containing pimaricin (20 mg/liter), ampicillin (125 mg/liter), rifampicin (10 mg/liter), and pentachloronitrobenzene (20 mg/liter). Four Pythium-like isolates were recovered after three days of incubation at 26°C, and purified using hyphal-tipping. Ten agar plugs (2×2 mm2) of each isolate were grown in 10 mL of 10% clarified V8 juice (cV8) in a 10 cm plate at 26°C for 3 days to produce mycelial mats, and then the cV8 was replaced with sterile water. To stimulate sporangial production, three to five drops of soil extract solution were added to each plate. Sporangia were terminal, ovoid to globose, and the size is 24 to 45.6 (mean 34.7) (n=10.8) in length x 23.6 to 36.0 (mean 29.8) (n=6.2) in width. Gametangia were not observed in cV8A or liquid media after 30 days. For colony morphology, the isolates were sub-cultured onto three solid microbial media (cV8A-PARP, potato dextrose agar, corn meal agar) . All isolates had identical morphological features in the three media. Complete ITS and partial LSU and cox2 gene regions were amplified using primer pairs ITS1/ITS4, NL1/NL4, and FM58/FM66 , respectively. The ITS, LSU, and cox2 sequences of isolate PC-dj1 (GenBank Acc. No. MW205746, MW208002, MW208003) were 100.00% (936/936 nt), 100.00% (772/772 nt), and 99.64% (554/556 nt) identical to those of JX985743, MT042003, and GU133521, respectively. We built a maximum-likelihood tree of Phytopythium species using the concatenated dataset (ITS, LSU, cox2) to observe interspecific differences. Based on the morphological characters and sequences, isolate PC-djl was identified as Phytopythium litorale . As the four isolates (PC-dj1, PC-dj2, PC-dj3 and PC-dj4) tested had identical morphological characters and molecular marker sequences, the pathogenicity of the representative isolate, PC-dj1, was tested using two inoculation methods on ten one-year-old R. pulchrum plants. For the first inoculation method, plants were removed from the pot, and their roots were rinsed with tap water to remove the soil. Each of these plants was placed in a glass flask containing 250 mL of sterile water and 10 blocks (10 x 10 mm2) of mycelial mats harvested from a three-day-old culture of P. litorale, while the other plant was placed in sterile water as a control, and incubated at 26°C. After three days, symptoms including crown rot, root rot and blight was observed on the inoculated plants whereas the control remained asymptomatic. For the second inoculation method, ten plants were dug up to expose the root ball. Ten three-day-old cV8A plugs (5×5 mm2) from a PC-dj1 culture or sterile cV8A plugs were evenly insert into the root ball of a plant before it was planted back into the original pots. Both plants were maintained in a growth chamber set at 26°C with a 12/12 h light/dark cycle and irrigated as needed. After 14 to 21 days, the inoculated plant had symptoms resembling those in the field , while the control plant remained asymptomatic. Each inoculation method was repeated at triplicate and the outcomes were identical. Phytopythium isolates with morphological features and sequences identical to those of PC-dj1 were recovered from rotted crown and root tissues of all inoculated plants. Previously, P. litorale was found causing diseases of apple and Platanus orientalis in Turkey, fruit rot and seedling damping-off of yellow squash in southern Georgia, USA. This is the first report of this species causing crown and root rot on R. pulchrum, an important ornamental plant species in China. Additional surveys are ongoing to determine the distribution of P. litorale in the city of Nanjing.

scholarly journals A new corticolous species of Mycena sect. Viscipelles (Basidiomycota: Agaricales) from the bark of a Living American elm tree in Texas, U.S.A.

2020 ◽  
Vol 14 (2) ◽  
pp. 167-185
Author(s):  
Brian A. Perry ◽  
Harold W. Keller ◽  
Edward D. Forrester ◽  
Billy G. Stone
Keyword(s):  
Sequence Data ◽  
Intermediate Stage ◽  
Morphological Characters ◽  
Morphological Features ◽  
Depth Of Field ◽  
Morphological Development ◽  
Fort Worth ◽  
Moist Chamber ◽  
American Elm ◽  
The North

A  Mycena species new to science was obtained from moist chamber cultures of trunk bark of a living American elm tree (Ulmus americana) located in the Fort Worth Botanic Garden, Tarrant County, Texas. This discovery was part of an ongoing study of corticolous myxomycetes on larger American elm trees occurring in Fort Worth nature parks. More than 15 American elm trees were sampled for trunk bark but only a single tree yielded  Mycena basidiomes. Collections of bark began in the summer of 2017 and continued until the beginning of 2020. Bark samples from the north, south and west side of the tree yielded fruit bodies of the mushroom in moist chamber culture. No fruit bodies were observed in nature nor were early formation stages on the underside of the bark. Crystals previously described in another study were present on the bark surfaces, edges, and undersides. Habit and morphological development were photographed using light microscopy applying multifocal imaging and computer stacking to increase depth of field. Basidiome development was observed and photographed from the earliest primordial beginning stage, the button stage, intermediate stage and the final emerging stalk elongation and mature cap formation stage. Mature mushroom development took from 9 to 21 days after wetting the bark in moist chamber cultures. Scanning electron microscopy was used to illustrate development of the button stage, emerging stalk and pileus stage, and the fully mature pileus, lamellae, and pseudocollarium. Morphological features and DNA sequence data confirmed that this  Mycena species was undescribed and distinct from other  Mycena taxa. Morphological features suggest placement of the novel taxon in  Mycena sect. Viscipelles, distinct from other members based on morphological characters and phylogenetic analysis.

scholarly journals Allosorex stenodus Fejfar, 1966 (Eulipotyphla, Soricidae): re-description of type material and re-interpretation of its fossil record

2020 ◽  
Vol 76 (1) ◽  
pp. 84-98
Author(s):  
Oldřich Fejfar ◽  
Wighart v. Koenigswald ◽  
Martin Sabol
Keyword(s):  
Fossil Record ◽  
Critical Evaluation ◽  
Morphological Characters ◽  
Microstructure Analysis ◽  
Karst Area ◽  
Eastern Asia ◽  
Enamel Microstructure ◽  
Fossil Remains ◽  
Karst Areas ◽  
Taxonomical Status

The original fossil record of Allosorex stenodus Fejfar, 1966 from Ivanovce (late Ruscinian, MN 15b) is redescribed and supplemented by the description of so far unpublished fossil remains, including upper dentition (P4 and M3) and a humerus fragment as well as the enamel microstructure analysis of m2. Based on the critical evaluation of other fossil remains from sites in Romania, Hungary, and France, the Ivanovce fossils are so far the only unquestionable recorded finds of A. stenodus in Europe, which can be considered as a local early Pliocene (MN 15) endemic species. Its occurrence is connected with the forested karst area along a broad valley of “pre-Váh” River, ecologically and climatically resembling the environment of modern karst areas in south-eastern Asia. Based on enamel microstructure analysis and unique mandible and dentition morphological characters, a separate taxonomical status of the species is also discussed.

Fossil preservation and the stratigraphic ranges of taxa

Paleobiology ◽  
1996 ◽  
Vol 22 (2) ◽  
pp. 121-140 ◽  
Author(s):  
Mike Foote ◽  
David M. Raup
Keyword(s):  
Fossil Record ◽  
Mammalian Species ◽  
Evolutionary Rates ◽  
Extinction Rate ◽  
Mammal Species ◽  
Original Distribution ◽  
Lower Ordovician ◽  
Stratigraphic Ranges ◽  
Fossil Preservation ◽  
Rule Out

The incompleteness of the fossil record hinders the inference of evolutionary rates and patterns. Here, we derive relationships among true taxonomic durations, preservation probability, and observed taxonomic ranges. We use these relationships to estimate original distributions of taxonomic durations, preservation probability, and completeness (proportion of taxa preserved), given only the observed ranges. No data on occurrences within the ranges of taxa are required. When preservation is random and the original distribution of durations is exponential, the inference of durations, preservability, and completeness is exact. However, reasonable approximations are possible given non-exponential duration distributions and temporal and taxonomic variation in preservability. Thus, the approaches we describe have great potential in studies of taphonomy, evolutionary rates and patterns, and genealogy.Analyses of Upper Cambrian-Lower Ordovician trilobite species, Paleozoic crinoid genera, Jurassic bivalve species, and Cenozoic mammal species yield the following results: (1) The preservation probability inferred from stratigraphic ranges alone agrees with that inferred from the analysis of stratigraphic gaps when data on the latter are available. (2) Whereas median durations based on simple tabulations of observed ranges are biased by stratigraphic resolution, our estimates of median duration, extinction rate, and completeness are not biased. (3) The shorter geologic ranges of mammalian species relative to those of bivalves cannot be attributed to a difference in preservation potential. However, we cannot rule out the contribution of taxonomic practice to this difference. (4) In the groups studied, completeness (proportion of species [trilobites, bivalves, mammals] or genera [crinoids] preserved) ranges from 60% to 90%. The higher estimates of completeness at smaller geographic scales support previous suggestions that the incompleteness of the fossil record reflects loss of fossiliferous rock more than failure of species to enter the fossil record in the first place.

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