scholarly journals Tiny pollen grains: first evidence of Saururaceae from the Late Cretaceous of western North America

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3434 ◽  
Author(s):  
Friðgeir Grímsson ◽  
Guido W. Grimm ◽  
Reinhard Zetter
Keyword(s):  
North America ◽  
Fossil Record ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
Modern Species ◽  
Extant Species ◽  
The Family ◽  
History Of ◽  
Western Eurasia

Background The Saururaceae, a very small family of Piperales comprising only six species in four genera, have a relatively scanty fossil record outside of Europe. The phylogenetic relationships of the four genera to each other are resolved, with the type genus Saururus occurring in both eastern North America and East Asia. No extant species occurs in western Eurasia. The most exceptional find so far has been an inflorescence with in-situ pollen, Saururus tuckerae S.Y.Sm. & Stockey from Eocene of North America with strong affinities to extant species of Saururus. Recent dated trees suggest, however, an Eocene or younger crown age for the family. Methods Dispersed fossil pollen grains from the Campanian (82–81 Ma) of North America are compared to dispersed pollen grains from the Eocene strata containing S. tuckerae, the Miocene of Europe, and extant members of the family using combined LM and SEM imaging. Results The unambiguous fossil record of the Saururaceae is pushed back into the Campanian (82–81 Ma). Comparison with re-investigated pollen from the Eocene of North America, the Miocene of Europe, and modern species of the family shows that pollen morphology in Saururaceae is highly conservative, and remained largely unchanged for the last 80 million years. Discussion Campanian pollen of Saururaceae precludes young (Eocene or younger) estimates for the Saururaceae root and crown age, but is in-line with maximum age scenarios. Saururus-type pollen appear to represent the primitive pollen morphology of the family. Often overlooked because of its small size, dispersed Saururaceae pollen may provide a unique opportunity to map the geographic history of a small but old group of Piperales, and should be searched for in Paleogene and Cretaceous sediment samples.

A taxonomic revision of the Pleistocene Hystrix (Hystricidae, Rodentia) from Eurasia with notes on the evolution of the family

2005 ◽  
Vol 74 (3-4) ◽  
pp. 301-312 ◽  
Author(s):  
D.J. van Weers
Keyword(s):  
Fossil Record ◽  
Taxonomic Revision ◽  
Extant Species ◽  
The Family ◽  
Asiatic Species

Measurements of many hundreds of the high-crowned cheek teeth of Hystrix specimens from the Euro-Asiatic Pleistocene in the collections of European and Asiatic institutions have been compared with extant species for a revision of the genus. A review is given about the extant genera and species of the family. The number of recognisable Euro-Asiatic species in the fossil record is reduced from eight to five. The European H. (A.) vinogradovi Argyropulo, 1941 is here considered to be a synonym of H. (A.) brachyura Linnaeus, 1758, and the three Asiatic species H. (H.) crassidens Lydekker, 1886, H. (H.) gigantea Van Weers, 1985 and H. (H.) magna Pei, 1987 are synonymized with H. (H.) refossa Gervais, 1852. Most of the Chinese fossil specimens are properly allocated to H. (H.) kiangsenensis Wang, 1931 instead of ‘H. subcristata’, and a neotype is indicated for this species. The distribution of the Indonesian Hystrix species is the result of several migration waves into Sundaland, and is not considered to be the result of ‘in situ’ evolution. Comparison of the Miocene material from the Siwaliks in India, described as Sivacanthion complicatus Colbert 1933, with extant and Pleistocene Atherurus results in allocation of this species to Atherurus karnuliensis Lydekker, 1886.

scholarly journals A morphological study of vertebral centra in extant species of pike, Esox (Teleostei: Esociformes)

2019 ◽  
Vol 7 ◽  
pp. 111-128
Author(s):  
Sinjini Sinha ◽  
Don B Brinkman ◽  
Alison M. Murray
Keyword(s):  
Late Cretaceous ◽  
Fossil Record ◽  
Morphological Study ◽  
Vertebral Column ◽  
Early History ◽  
Vertebral Centra ◽  
Extant Species ◽  
The Family ◽  
Early Paleocene ◽  
History Of

            Isolated centra of members of the Esocidae occur frequently in vertebrate microfossil localities of Late Cretaceous and early Paleocene age and are an important source of data on the early history of the family. However, morphological variation along the vertebral column can lead to incorrect interpretations of diversity if they are not recognized. To facilitate the use of centra for interpreting the diversity and distribution of esocids in Cretaceous vertebrate microfossil localities, the variation along the column in five extant species of esocids is described. Comparison with Cretaceous centra referred to the Esocidae allows identification of a series of features in which species of Esox differ from basal members of the family. These include the presence of a mid-ventral groove bordered by a pair of low budges on centra in the anterior end of the column, and antero-lateral processes on the posterior abdominal and anterior caudal centra. These differences provide a basis for recognizing early occurrences of the genus Esox in the fossil record and thus will allow centra to be used to document the timing of origin of the genus.

Pollen morphology and chromosome numbers of the family Plantaginaceae in North America

1968 ◽  
Vol 46 (4) ◽  
pp. 349-361 ◽  
Author(s):  
I. J. Bassett ◽  
C. W. Crompton
Keyword(s):  
North America ◽  
Chromosome Numbers ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
General Distribution ◽  
Fossil Pollen ◽  
Pollen Production ◽  
The Family

Pollen grains of 28 Plantago and one Littorella species found in North America are described in detail and a key to their identification is presented. The general distribution, habitats, pollen production per anther, flower types (i.e. cleistogamous or chasmogamous) are given for each taxon and in addition the chromosome numbers are reported for 17 Plantago species and Littorella americana. Evidence is presented that Plantago fastigiata does not belong to the section Leucopsyllium. Fossil pollen grains of the Plantaginaceae, most likely to be found in any quantity in postglacial deposits of the Pleistocene epoch, are as follows: Plantago rugelii; P. cordata; P. eriopoda; P. macrocarpa; P. maritima; P. canescens; and Littorella americana.

Review of Eohiodon (Teleostei: Osteoglossomorpha) from western North America, with a phylogenetic reassessment of Hiodontidae

1997 ◽  
Vol 71 (6) ◽  
pp. 1109-1124 ◽  
Author(s):  
Li Guo-Qing ◽  
Mark V. H. Wilson ◽  
Lance Grande
Keyword(s):  
North America ◽  
Sister Group ◽  
Sensu Stricto ◽  
Valid Species ◽  
Western North America ◽  
Extant Species ◽  
The Family ◽  
Fossil Records ◽  
Fossil Genus ◽  
Freshwater Teleosts

Review of recently collected material of Eohiodon from North America suggests that there are two valid species, E. rosei (Hussakof) and E. woodroffi Wilson. Eohiodon falcatus Grande is identical to E. woodruffi in known skeletal features and nearly all meristic features and is treated as a junior synonym of the latter. The fossil genus Eohiodon Cavender differs from Hiodon Lesueur, which is known from both fossil and extant species, in numerous meristic and osteological features. The caudal skeleton in Eohiodon is nearly identical to that in Hiodon.The traditionally accepted Notopteroidei, containing Lycopteridae, Hiodontidae, and Notopteridae, is a polypheletic group. The Asian fossil family Lycopteridae is not more closely related to Hiodontidae than it is to other taxa in the Osteoglossomorpha, but is sister to all other Osteoglossomorpha. The Hiodontiformes sensu stricto, including only the family Hiodontidae, is the sister-group of the Osteoglossiformes. This family is not more closely related to notopterids than to other taxa in Osteoglossiformes. The Notopteridae are most closely related to the Mormyroidea; together they and the fossil family Ostariostomidae constitute the sister-group of the Osteoglossoidei.Fossil records of Hiodontiformes sensu stricto and Notopteroidei indicate a widespread pre-Neogene biogeographic range of these freshwater teleosts, suggesting that extinction must have been involved in the Cenozoic evolution of these two osteoglossomorph sublineages.

Comparative morphological, anatomical, micromorphological, and palynological studies on the genera Opopanax and Crenosciadium (Apiaceae)

Phytotaxa ◽  
2018 ◽  
Vol 372 (1) ◽  
pp. 35 ◽  
Author(s):  
ÖZLEM ÇETIN ◽  
MUSTAFA ÇELIK
Keyword(s):  
Cross Sections ◽  
Mediterranean Region ◽  
Pollen Morphology ◽  
Pollen Grains ◽  
Molecular Data ◽  
Monotypic Genus ◽  
Western Asia ◽  
The Family ◽  
Surface Ornamentation ◽  
Fruit Surface

In the present study, morphological, micromorphological, palynological and anatomical characteristics of the genera Opopanax and Crenosciadium are reviewed and compared. The genus Opopanax is distributed in southern Europe, the Mediterranean region and Western Asia, and it is represented by three species in Turkey. Crenosciadium is a poorly known monotypic genus from Turkey, recently treated as synonym in Opopanax. Expanded descriptions, phenology, geographic distributions, and images of habitus of Opopanax and Crenosciadium are given. The differences between the two genera are discussed. The pollen morphology of Opopanax and Crenosciadium is studied by SEM and LM. The palynological results confirmed the stenopalynous characteristic of the family Apiaceae, and revealed that the pollen grains of both genera are perprolate in shape. Also fruit surface ornamentation of both genera is typically striate, and epidermal cells are polygonal or elongated in one direction. Cross-sections of mature fruits are examined and a detailed anatomical description is presented. Mericarp shape and width are very useful characters for discrimination between Opopanax and Crenosciadium; mericarp ribs are also very significant characteristics to discriminate both genera. Our findings, together with previous molecular data, clearly indicate that Crenosciadium differs considerably from Opopanax, and therefore it should be accepted at genus rank.

scholarly journals Pollen characters as taxonomic evidence in some species of Dipsacaceae from Iran

2017 ◽  
Vol 24 (2) ◽  
pp. 129-136 ◽  
Author(s):  
Ebadi-Nahari Mostafa ◽  
Nikzat-Siahkolaee Sedigheh ◽  
Eftekharian Rosa
Keyword(s):  
Pollen Morphology ◽  
Pollen Grains ◽  
Pollen Grain ◽  
Pollen Type ◽  
Upgma Tree ◽  
Pollen Characters ◽  
Exine Ornamentation ◽  
The Family ◽  
The World ◽  
Plant Taxon

Pollen morphology of nine species representing four genera: Cephalaria Schrad, Dipsacus L., Pterocephalus Vaill. and Scabiosa L. of the family Dipsacaceae in Iran has been investigated by means of scanning electron microscopy (SEM). The results showed that pollen grains were triporate and tricolpate. The pollen type of Scabiosa rotata Bieb. (tri- and tetraporate) is the first report in the world. The sizes of pollen grains fall into the classification group magna (pollen grain diameter 50–100 μm). Pollen shapes vary from preoblate to prolate and their polar views were triangulate and lobate. The exine ornamentation varies from gemmate in S. rotata to spinulate in the rest studied species. Species of Scabiosa have been dispersed in UPGMA tree that this confirmed the previous studies about taxonomic problems and species complexity in this genus. These results show the transfer of the some Scabisoa species to Lomelosia Raf. based on palynological characters. Pollen morphology of the family is helpful at the generic and specific level.Bangladesh J. Plant Taxon. 24(2): 129–136, 2017 (December)

Fossil flower of Staphylea L. from the Miocene amber of Mexico: New evidence of the Boreotropical Flora in low-latitude North America

2017 ◽  
Vol 108 (4) ◽  
pp. 471-478 ◽  
Author(s):  
Ana L. Hernández-Damián ◽  
Sergio R. S. Cevallos-Ferriz ◽  
Alma R. Huerta-Vergara
Keyword(s):  
North America ◽  
Northern Hemisphere ◽  
Fossil Record ◽  
First Record ◽  
High Latitudes ◽  
Low Latitude ◽  
Southern Mexico ◽  
Apparent Lack ◽  
History Of ◽  
New Evidence

ABSTRACTA new flower preserved in amber in sediments of Simojovel de Allende, México, is identified as an extinct member of Staphyleaceae, a family of angiosperms consisting of only three genera (Staphylea, Turpinia and Euscaphis), which has a large and abundant fossil record and is today distributed over the Northern Hemisphere. Staphylea ochoterenae sp. nov. is the first record of a flower for this group, which is small, pedicelled, pentamer, bisexual, with sepals and petals with similar size, dorsifixed anthers and superior ovary. Furthermore, the presence of stamens with pubescent filaments allows close comparison with extant flowers of Staphylea bulmada and S. forresti, species currently growing in Asia. However, their different number of style (one vs. three) and the apparent lack of a floral disc distinguish them from S. ochoterenae. The presence of Staphyleaceae in southern Mexico ca. 23 to 15My ago is evidence of the long history of integration of vegetation in low-latitude North America, in which some lineages, such as Staphylea, could move southwards from high latitudes of the Northern Hemisphere, as part of the Boreotropical Flora. In Mexico it grew in association with tropical elements, as suggested by the fossil record of the area.

scholarly journals Population structure and demographic history of the chukar partridge Alectoris chukar in China

2013 ◽  
Vol 59 (4) ◽  
pp. 458-474 ◽  
Author(s):  
Sen Song ◽  
Shijie Bao ◽  
Ying Wang ◽  
Xinkang Bao ◽  
Bei An ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
North America ◽  
Demographic History ◽  
Population Expansion ◽  
Northwest China ◽  
Population History ◽  
Extant Species ◽  
History Of ◽  
Chukar Partridge

Abstract Pleistocene climate fluctuations have shaped the patterns of genetic diversity observed in extant species. Although the effects of recent glacial cycles on genetic diversity have been well studied on species in Europe and North America, genetic legacy of species in the Pleistocene in north and northwest of China where glaciations was not synchronous with the ice sheet development in the Northern Hemisphere or or had little or no ice cover during the glaciations’ period, remains poorly understood. Here we used phylogeographic methods to investigate the genetic structure and population history of the chukar partridge Alec-toris chukar in north and northwest China. A 1,152 – 1,154 bp portion of the mtDNA CR were sequenced for all 279 specimens and a total number of 91 haplotypes were defined by 113 variable sites. High levels of gene flow were found and gene flow estimates were greater than 1 for most population pairs in our study. The AMOVA analysis showed that 81% and 16% of the total genetic variability was found within populations and among populations within groups, respectively. The demographic history of chukar was examined using neutrality tests and mismatch distribution analyses and results indicated Late Pleistocene population expansion. Results revealed that most populations of chukar experienced population expansion during 0.027 ? 0.06 Ma. These results are at odds with the results found in Europe and North America, where population expansions occurred after Last Glacial Maximum (LGM, 0.023 to 0.018 Ma). Our results are not consistent with the results from avian species of Tibetan Plateau, either, where species experienced population expansion following the retreat of the extensive glaciation period (0.5 to 0.175 Ma).

First fossil record of a nymph (Ephemeroptera, Teloganellidae) from the Indian subcontinent

Zootaxa ◽  
2020 ◽  
Vol 4838 (1) ◽  
pp. 137-142
Author(s):  
PRIYA AGNIHOTRI ◽  
KAJAL CHANDRA ◽  
ANUMEHA SHUKLA ◽  
HUKAM SINGH ◽  
RAKESH C. MEHROTRA
Keyword(s):  
Fossil Record ◽  
Indian Subcontinent ◽  
Early Eocene ◽  
Lignite Mine ◽  
Modern Species ◽  
The Family ◽  
Mayfly Nymph ◽  
Modern Genus ◽  
First Time ◽  
A New Species

A fossil of a mayfly nymph that shows similarities with the modern genus Teloganella Ulmer, 1939 of the family Teloganellidae is recorded for the first time from the Indian subcontinent. It is systematically described from the Gurha lignite mine of Bikaner, Rajasthan which belongs to the Palana Formation (late Paleocene-early Eocene). As assignment of the fossil to a modern species of Teloganella is difficult due to indistinguishable location of gills in the impression, a new species, Teloganella gurhaensis Agnihotri et al., sp. nov. is instituted to include this fossil naiad resembling the extant Teloganella. 

scholarly journals A fully resolved backbone phylogeny reveals numerous dispersals and explosive diversifications throughout the history of Asteraceae

2019 ◽  
Vol 116 (28) ◽  
pp. 14083-14088 ◽  
Author(s):  
Jennifer R. Mandel ◽  
Rebecca B. Dikow ◽  
Carolina M. Siniscalchi ◽  
Ramhari Thapa ◽  
Linda E. Watson ◽  
...  
Keyword(s):  
Middle Eocene ◽  
Range Shift ◽  
Flowering Plant ◽  
Migration Routes ◽  
Biogeographic Patterns ◽  
Extant Species ◽  
The Family ◽  
History Of ◽  
Flowering Plant Species ◽  
Patterns And Processes

The sunflower family, Asteraceae, comprises 10% of all flowering plant species and displays an incredible diversity of form. Asteraceae are clearly monophyletic, yet resolving phylogenetic relationships within the family has proven difficult, hindering our ability to understand its origin and diversification. Recent molecular clock dating has suggested a Cretaceous origin, but the lack of deep sampling of many genes and representative taxa from across the family has impeded the resolution of migration routes and diversifications that led to its global distribution and tremendous diversity. Here we use genomic data from 256 terminals to estimate evolutionary relationships, timing of diversification(s), and biogeographic patterns. Our study places the origin of Asteraceae at ∼83 MYA in the late Cretaceous and reveals that the family underwent a series of explosive radiations during the Eocene which were accompanied by accelerations in diversification rates. The lineages that gave rise to nearly 95% of extant species originated and began diversifying during the middle Eocene, coincident with the ensuing marked cooling during this period. Phylogenetic and biogeographic analyses support a South American origin of the family with subsequent dispersals into North America and then to Asia and Africa, later followed by multiple worldwide dispersals in many directions. The rapid mid-Eocene diversification is aligned with the biogeographic range shift to Africa where many of the modern-day tribes appear to have originated. Our robust phylogeny provides a framework for future studies aimed at understanding the role of the macroevolutionary patterns and processes that generated the enormous species diversity of Asteraceae.

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