Correlation of NW European Purbeck-Wealden (nonmarine Lower Cretaceous) as seen from the English type-areas

Allen, P.; Wimbledon, William A.P.

doi:10.1016/0195-6671(91)90005-w

Cited by 148 publications

(69 citation statements)

References 31 publications

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“…The age range of the Purbeck-Wealden of England thus lies between 146 and 125 Myr (Harland et al 1989) and 141-119 Myr (Bralower et al 1990), giving a total duration of between 21 and 22 Myr (see the discussion in Allen & Wimbledon (1991)) for the existence of A. leguminella. Thus far, Darwinula stevensoni (the most common extant darwinulid) was, together with Microdarwinula zimmeri, the longest living ancient asexual animal species (Straub 1952) with a documented stratigraphical range of 20-25 Myr.…”

Section: Discussionmentioning

confidence: 99%

“…The sampled horizon, with a thickness of ca. 0.25 m, lies within the lower part of the Cypridea granulosa Subzone (Theriosynoecum forbesi Biozone) of Horne (1995), below the Cinder Bed Member that is sometimes taken to represent the Jurassic-Cretaceous boundary (but see Allen & Wimbledon (1991) for a discussion) and is therefore most probably of latest Jurassic age. The assemblage also contained the age-diagnostic cypridoidean ostracod Cypridea granulosa granulosa ( J. de C. Sowerby 1836).…”

Section: (A) Materialsmentioning

confidence: 99%

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How ancient are ancient asexuals?

Martens

Rossetti

Horne

2003

Proc. R. Soc. Lond. B

137

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Ancient asexual animal groups, such as bdelloid rotifers and darwinuloid ostracods, are excellent model organisms to study the effects of long-term asexuality. However, the absolute length of time that these groups have been fully asexual is mostly ignored. In the case of the darwinuloid ostracods, the fossil record shows that sexual reproduction disappeared almost completely after the end of Permian mass extinction (ca. 245 Myr ago), although several putative records of males from the Mesozoic obscure the exact timeframe of obligate asexuality in darwinuloids. Here, we re-examine the Mesozoic darwinuloid records, with regard to the reproductive mode of the assemblages. Three criteria to distinguish males in fossil populations (lack of brood pouch, position of muscle scars and size dimorphism) are used here to test for the presence of males in darwinuloid assemblages. A large, well-preserved assemblage of Darwinula leguminella (Forbes 1885) from the latest Jurassic (ca. 145 Myr ago) of England is found to be markedly variable in size and shape, but nevertheless turns out to be an all female assemblage. The exceptional preservation of the material also allows the re-assignment of this species to the extant darwinuloid genus Alicenula. All other putative dimorphic darwinuloid records from the Mesozoic are re-examined using the same criteria. The hypothesis that these assemblages represent bisexual populations is rejected for all post-Triassic (ca. 208 Myr ago) records.

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Section: Discussionmentioning

confidence: 99%

Section: (A) Materialsmentioning

confidence: 99%

How ancient are ancient asexuals?

Martens

Rossetti

Horne

2003

Proc. R. Soc. Lond. B

137

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“…Age: lower Valanginian (Allen and Wimbledon 1991). Etymology: Torus -Latin for "rounded" and "ilion" Latin for ilium, in reference to the rounded postacetabular process.…”

Section: Theiophytalia Kerri Brill and Carpenter 2006mentioning

confidence: 99%

Early and Middle Cretaceous Iguanodonts in Time and Space

Carpenter¹,

Ishida²

2010

J. iber. geol.

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Iguanodontes del Cretácico temprano y "medio" en el tiempo y en el espacio Abstract Recent discoveries of diverse iguanodonts throughout the Cedar Mountain Formation (Utah, USA) have led us to assess the global diversity of Early Cretaceous iguanodonts. The record in England is more diverse than previously recognized due to Iguanodon being a wastebasket genus throughout the Twentieth Century. Several new taxa, previously recognized as generically distinct by Harry Grovier Seeley, are named. The spatial and temporal distributions of iguanodonts are plotted on global maps as a key to understanding the origin of the Cedar Mountain Formation iguanodonts. Keywords: Early Cretaceous, Iguanodonts, Dinosauria ResumenLos recientes descubrimientos de diversos iguanodontes en la Formación Cedar Mountain (Utah, EE.UU.) nos han llevado a valorar la diversidad global de los iguanodontes del Cretácico temprano. El registro en Inglaterra es más diverso de lo que previamente se ha reconocido, debido a que Iguanodon ha sido tratado como un género "cajón de sastre" a lo largo de todo el siglo XX. Varios de los nuevos taxones, previamente reconocidos como genéricamente distintos por Harry Seeley Grovier, se denominan. La distribución espacial y temporal de Iguanodontia se superponen sobre mapas globales como una clave para comprender el origen de los iguanodontes de la Formación Cedar Mountain.

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“…Friis et al (2000aFriis et al ( , 2011 stated that Pennipollis ranges from the Barremian to the Cenomanian or Turonian, but the oldest well-dated records are early Aptian, confirming the use of Pennipollis as a guide fossil for Aptian and younger sediments (Penny 1988a;Doyle 1992;Heimhofer et al 2007). Hughes et al (1979) labeled the oldest grains of the Pennipollis type (Retisulc-dubdent) as Barremian-Aptian, but these were from the upper Vectis Formation, which has been redated by magnetostratigraphy as earliest Aptian (Kerth and Hailwood 1988;Allen and Wimbledon 1991;Hughes 1994). Pennipollis also appears above the base of the Aptian in Portuguese marine sections (Heimhofer et al 2005(Heimhofer et al , 2007.…”

mentioning

confidence: 99%

Integrating Early Cretaceous Fossils into the Phylogeny of Living Angiosperms: ANITA Lines and Relatives of Chloranthaceae

Doyle

Endress

2014

International Journal of Plant Sciences

111

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Editor: Patrick S. HerendeenPremise of research. Discoveries of fossil flowers in Cretaceous rocks offer improved evidence for relationships with living clades, but for more secure inferences formal phylogenetic analyses are desirable. We extend previous analyses of magnoliids, monocots, and basal eudicots to Aptian, Albian, and Cenomanian fossils related to the basal "ANITA" lines and Chloranthaceae.Methodology. We performed parsimony analyses of a morphological data set of Recent angiosperms and published fossils, with the arrangement of Recent taxa constrained to backbone trees based primarily on molecular data.Pivotal results. Not only Monetianthus (as previously inferred) but also Carpestella is nested within Nymphaeaceae, while Pluricarpellatia may be a stem relative of Cabombaceae or Nymphaeaceae. Anacostia (with Similipollis pollen) is nested within Austrobaileyales. The position of Couperites (with Clavatipollenites pollen) is ambiguous: it may be on the stem lineage of Chloranthaceae (and Ceratophyllum, if this extant aquatic is related to Chloranthaceae), nested in Chloranthaceae, or more basal. Plants with Asteropollis pollen and reduced tepals are related to the chloranthaceous genus Hedyosmum. Zlatkocarpus, which also has a reduced perianth, may be either a stem relative or a crown group member of Chloranthaceae. Plants that produced loosely reticulate Pennipollis pollen are more likely related to Chloranthaceae and/or Ceratophyllum than to monocots. We confirm that Canrightia, with bisexual flowers and a reduced perianth, is a stem relative of Chloranthaceae. Despite similarities to Piperales, Appomattoxia (with Tucanopollis pollen) is more likely near the base of the ANITA grade or related to Chloranthaceae and/or Ceratophyllum.Conclusions. The Cretaceous rise of angiosperms involved the radiation not only of magnoliids, eudicots, and monocots but also of basal ANITA lines, including both aquatic Nymphaeales and woody groups. Our results reaffirm the early diversity of Chloranthaceae and clarify their floral evolution, in which a shift to unisexual flowers preceded loss of the perianth.

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Correlation of NW European Purbeck-Wealden (nonmarine Lower Cretaceous) as seen from the English type-areas

Cited by 148 publications

References 31 publications

How ancient are ancient asexuals?

How ancient are ancient asexuals?

Early and Middle Cretaceous Iguanodonts in Time and Space

Integrating Early Cretaceous Fossils into the Phylogeny of Living Angiosperms: ANITA Lines and Relatives of Chloranthaceae

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Correlation of NW European Purbeck-Wealden (nonmarine Lower Cretaceous) as seen from the English type-areas

Cited by 148 publications

References 31 publications

How ancient are ancient asexuals?

How ancient are ancient asexuals?

Early and Middle Cretaceous Iguanodonts in Time and Space

Integrating Early Cretaceous Fossils into the Phylogeny of Living Angiosperms: ANITA Lines and Relatives of Chloranthaceae

Contact Info

Product

Resources

About

Early and Middle Cretaceous Iguanodonts in Time and Space