scholarly journals Terrestrial invertebrates in the Rhynie chert ecosystem

2017 ◽  
Vol 373 (1739) ◽  
pp. 20160493 ◽  
Author(s):  
Jason A. Dunlop ◽  
Russell J. Garwood
Keyword(s):  
Early Life ◽  
Hot Springs ◽  
Terrestrial Ecosystem ◽  
Early Devonian ◽  
Male And Female ◽  
Terrestrial Invertebrates ◽  
Plant Parasitism ◽  
Liquid Feeding ◽  
Rhynie Chert ◽  
Nematode Worm

The Early Devonian Rhynie and Windyfield cherts remain a key locality for understanding early life and ecology on land. They host the oldest unequivocal nematode worm (Nematoda), which may also offer the earliest evidence for herbivory via plant parasitism. The trigonotarbids (Arachnida: Trigonotarbida) preserve the oldest book lungs and were probably predators that practiced liquid feeding. The oldest mites (Arachnida: Acariformes) are represented by taxa which include mycophages and predators on nematodes today. The earliest harvestman (Arachnida: Opiliones) includes the first preserved tracheae, and male and female genitalia. Myriapods are represented by a scutigeromorph centipede (Chilopoda: Scutigeromorpha), probably a cursorial predator on the substrate, and a putative millipede (Diplopoda). The oldest springtails (Hexapoda: Collembola) were probably mycophages, and another hexapod of uncertain affinities preserves a gut infill of phytodebris. The first true insects (Hexapoda: Insecta) are represented by a species known from chewing (non-carnivorous?) mandibles. Coprolites also provide insights into diet, and we challenge previous assumptions that several taxa were spore-feeders. Rhynie appears to preserve a largely intact community of terrestrial animals, although some expected groups are absent. The known fossils are (ecologically) consistent with at least part of the fauna found around modern Icelandic hot springs. This article is part of a discussion meeting issue ‘The Rhynie cherts: our earliest terrestrial ecosystem revisited’.

New gametophytes from the Early Devonian Rhynie chert

2003 ◽  
Vol 94 (4) ◽  
pp. 411-428 ◽  
Author(s):  
Hans Kerp ◽  
Nigel H. Trewin ◽  
Hagen Hass
Keyword(s):  
Reproductive Cycle ◽  
Land Plants ◽  
Monotypic Genus ◽  
Early Devonian ◽  
Male And Female ◽  
Rhynie Chert ◽  
Dense Stand

ABSTRACTSeveral new gametophytes are described from the Early Devonian Rhynie chert. The new monotypic genus Remyophyton, being the gametophyte of Rhynia, is represented by a dense stand of in situ preserved gametophytes with antheridia- and archegonia-bearing axes. The gametophytes are remarkably small in comparison to those of other Rhynie chert plants. The generic diagnoses of Lyonophyton and Langiophyton are emended to include archegonia- and antheridiabearing axes. All essential stages of the reproductive cycle, i.e. sporophytes, and male and female gametophytes, can now be demonstrated for three of the six land plants from the Rhynie chert, i.e. Rhynia gwynne-vaughanii, Aglaophyton major and Horneophyton lignieri.

scholarly journals Palaeoecology and palaeophytogeography of the Rhynie chert plants: further evidence from integrated analysis of in situ and dispersed spores

2017 ◽  
Vol 373 (1739) ◽  
pp. 20160491 ◽  
Author(s):  
Charles H. Wellman
Keyword(s):  
Hot Springs ◽  
Terrestrial Ecosystem ◽  
Land Plants ◽  
Integrated Analysis ◽  
Exceptional Preservation ◽  
Rhynie Chert ◽  
Floodplain Deposits ◽  
Early Land

The remarkably preserved Rhynie chert plants remain pivotal to our understanding of early land plants. The extraordinary anatomical detail they preserve is a consequence of exceptional preservation, by silicification, in the hot-springs environment they inhabited. However, this has prompted questions as to just how typical of early land plants the Rhynie chert plants really are. Some have suggested that they were highly adapted to the unusual hot-springs environment and are unrepresentative of ‘normal’ plants of the regional flora. New quantitative analysis of dispersed spore assemblages from the stratigraphical sequence of the Rhynie outlier, coupled with characterization of the in situ spores of the Rhynie chert plants, permits investigation of their palaeoecology and palaeophytogeography. It is shown that the Rhynie inland intermontane basin harboured a relatively diverse flora with only a small proportion of these plants actually inhabiting the hot-springs environment. However, the flora of the Rhynie basin differed from coeval lowland floodplain deposits on the same continent, as it was less diverse, lacked some important spore groups and contained some unique elements. At least some of the Rhynie plants (e.g. Horneophyton lignieri ) existed outside the hot-springs environment, inhabiting the wider basin, and were indeed palaeogeographically widespread. They probably existed in the hot-springs environment because they were preadapted to this unstable and harsh setting. This article is part of a discussion meeting issue ‘The Rhynie cherts: our earliest terrestrial ecosystem revisited’.

scholarly journals An evidence-based 3D reconstruction of Asteroxylon mackiei the most complex plant preserved from the Rhynie chert

2021 ◽  
Author(s):  
Alexander J Hetherington ◽  
Siobhán L Bridson ◽  
Anna Lee Jones ◽  
Hagen Hass ◽  
Hans Kerp ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
Early Life ◽  
3D Structure ◽  
Terrestrial Ecosystem ◽  
The Body ◽  
Evidence Based ◽  
Ancestral State ◽  
Leafy Shoot ◽  
Rhynie Chert ◽  
Development And Evolution

The 407-million-year-old Rhynie chert preserves the earliest terrestrial ecosystem and informs our understanding of early life on land. However, our knowledge of the 3D structure, and development of these plants is still rudimentary. Here we used digital 3D reconstruction techniques to produce the first complete reconstruction of the lycopsid Asteroxylon mackiei, the most complex plant in the Rhynie chert. The reconstruction reveals the organisation of the three distinct axes types — leafy shoot axes, root-bearing axes and rooting axes — in the body plan. Combining this reconstruction with developmental data from fossilised meristems, we demonstrate that the A. mackiei rooting axis — a transitional lycophyte organ between the rootless ancestral state and true roots — developed from root-bearing axes by anisotomous dichotomy. Our discovery demonstrates how this unique organ developed, and highlights the value of evidence-based reconstructions for understanding the development and evolution of the first complex plants on Earth.

Subaqueous silicification of the contents of small ponds in an Early Devonian hot-spring complex, Rhynie, Scotland

2003 ◽  
Vol 40 (11) ◽  
pp. 1697-1712 ◽  
Author(s):  
Nigel H Trewin ◽  
Stephen R Fayers ◽  
Ruth Kelman
Keyword(s):  
National Park ◽  
Hot Springs ◽  
Hot Spring ◽  
Aquatic Biota ◽  
Early Devonian ◽  
Climatic Extremes ◽  
Rhynie Chert ◽  
Freshwater Biota ◽  
Shallow Ponds ◽  
Surface Environment

The Early Devonian Rhynie and Windyfield cherts of northeast Scotland originated as siliceous sinters deposited by hot springs. Silicification affected both subaerial and subaqueous environments, preserving a diverse terrestrial and freshwater biota. Cherts originally deposited in small shallow pools can be recognised on the basis of both texture and fossil content. Textures comprise clotted and microcoprolitic textures, bacterial coatings on plant axes that can be stromatolitic, and a variety of bacterial and fungal meshworks. The crustacean Lepidocaris, the euthycarcinoid Heterocrania, the charophyte alga Palaeonitella, and chytrid fungi are typical elements of the aquatic biota. Observations of modern hot springs in Yellowstone National Park, Wyoming, U.S.A., demonstrate that shallow ponds and streams on low-angle outwash areas and dormant vent orifices provide suitable environmental analogues. Textures comparable to those described from Rhynie are recorded from Yellowstone sinters, but examples of the rapid and complete silicification of delicate organic structures as seen in a few of the Rhynie chert beds have not been noted. Petrographic textures comparable to those seen in the cherts of freshwater origin from Rhynie occur in modern stream sinters at Yellowstone, where they form from waters at 20–28 °C and with a pH of 8.7. This similarity occurs despite differences in environment at Yellowstone, such as the oxidizing surface environment, water table fluctuations, complex modern vegetation, fixing of silica by diatoms, and climatic extremes. Thus there are close similarities between textures seen in the Rhynie cherts and Yellowstone sinters deposited in freshwater pools and streams by hot springs.

scholarly journals A review of active hot-spring analogues of Rhynie: environments, habitats and ecosystems

2017 ◽  
Vol 373 (1739) ◽  
pp. 20160490 ◽  
Author(s):  
Alan Channing
Keyword(s):  
Hot Springs ◽  
Hot Spring ◽  
Terrestrial Ecosystem ◽  
Surface Expression ◽  
Geothermal Systems ◽  
Alkali Chloride ◽  
Shallow Subsurface ◽  
Elevated Salinity ◽  
Run Off ◽  
Rhynie Chert

The Lower Devonian Rhynie chert formed as silica sinter entombed an early terrestrial ecosystem. Silica sinter precipitates only from water flowing from alkali-chloride hot springs and geysers, the surface expression of crustal-scale geothermal systems that form low-sulfidation mineral deposits in the shallow subsurface. Active alkali-chloride hot springs at Yellowstone National Park create a suite of geothermally influenced environments; vent pools, sinter aprons, run-off streams, supra-apron terrace pools and geothermal wetlands that are habitats for modern hot-spring ecosystems. The plant-rich chert, which makes Rhynie internationally famous, probably formed in low-temperature environments at the margins of a sinter apron where frequent flooding by geothermal water and less frequent flooding by river waters created ephemeral to permanent wetland conditions. Here, the plants and associated microbes and animals would be immersed in waters with elevated temperature, brackish salinity, high pH and a cocktail of phytotoxic elements which created stresses that the fossil ecosystem must have tolerated. The environment excluded coeval mesophytic plants, creating a low-diversity hot-spring flora. Comparison with Yellowstone suggests the Rhynie plants were preadapted to their environment by life in more common and widespread environments with elevated salinity and pH such as coastal marshes, salt lakes, estuaries and saline seeps. This article is part of a discussion meeting issue ‘The Rhynie cherts: our earliest terrestrial ecosystem revisited’.

scholarly journals An evidence-based 3D reconstruction of Asteroxylon mackiei, the most complex plant preserved from the Rhynie chert

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Alexander J Hetherington ◽  
Siobhán L Bridson ◽  
Anna Lee Jones ◽  
Hagen Hass ◽  
Hans Kerp ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
Vascular Plants ◽  
3D Structure ◽  
Terrestrial Ecosystem ◽  
The Body ◽  
Evidence Based ◽  
Ancestral State ◽  
Early Devonian ◽  
Rhynie Chert ◽  
Development And Evolution

The Early Devonian Rhynie chert preserves the earliest terrestrial ecosystem and informs our understanding of early life on land. However, our knowledge of the 3D structure, and development of these plants is still rudimentary. Here we used digital 3D reconstruction techniques to produce the first well-evidenced reconstruction of the structure and development of the rooting system of the lycopsid Asteroxylon mackiei, the most complex plant in the Rhynie chert. The reconstruction reveals the organisation of the three distinct axis types – leafy shoot axes, root-bearing axes, and rooting axes – in the body plan. Combining this reconstruction with developmental data from fossilised meristems, we demonstrate that the A. mackiei rooting axis – a transitional lycophyte organ between the rootless ancestral state and true roots – developed from root-bearing axes by anisotomous dichotomy. Our discovery demonstrates how this unique organ developed and highlights the value of evidence-based reconstructions for understanding the development and evolution of the first complex vascular plants on Earth.

scholarly journals Organs and tissues of Rhynie chert plants

2017 ◽  
Vol 373 (1739) ◽  
pp. 20160495 ◽  
Author(s):  
Hans Kerp
Keyword(s):  
Secondary Wall ◽  
Major Part ◽  
Terrestrial Ecosystem ◽  
Regular Pattern ◽  
Intercellular Spaces ◽  
Early Devonian ◽  
Short Stalk ◽  
Rhynie Chert ◽  
Thin Walled

The Early Devonian Rhynie chert and the nearby Windyfield chert contain the oldest in situ preserved terrestrial ecosystem. Two of the seven species of anatomically preserved land plants had naked axes, one an axis with a more or less regular pattern of short-longitudinal ribs, two species had spiny axes and one species had small leaf-like appendages. All plants mainly consist of parenchymatous tissues. In some species, conducting elements comprise uniformly thickened thick-walled cells resembling hydroids of larger bryophytes, whereas others have real tracheids with annular and/or spiral secondary wall thickenings. True phloem has never been demonstrated but in all species the thick-walled water-conducting cells are encircled by a zone of thin-walled cells without intercellular spaces. The cortex is differentiated into two or three zones and forms the major part of the axes; in one species the cells of the middle cortex are sclerified. Some species have a hypodermis. In all species the epidermis is covered by a well-developed cuticle. Sporangia are known from all species. Sporangia are spindle-shaped, lobed or kidney-shaped and attached terminally or laterally with a short stalk. Gametophytes of four species have been described. Gametophytes are unisexual, isomorphic but much smaller than the sporophytes. This article is part of a discussion meeting issue ‘The Rhynie cherts: our earliest terrestrial ecosystem revisited’.

Charophyte algae from the Rhynie chert

2003 ◽  
Vol 94 (4) ◽  
pp. 445-455 ◽  
Author(s):  
Ruth Kelman ◽  
Monique Feist ◽  
Nigel H. Trewin ◽  
Hagen Hass
Keyword(s):  
National Park ◽  
Hot Springs ◽  
Hot Spring ◽  
Single Layer ◽  
Parent Plant ◽  
Early Devonian ◽  
Apical Pore ◽  
Molecular Studies ◽  
Rhynie Chert

ABSTRACTThe discovery of new specimens of Palaeonitella cranii (Kidston & Lang) Pia in the Early Devonian Rhynie chert permits the classification of this charophyte alga. This relatively small charophyte is composed of multicellular furcating branchlets with antheridia attached to the parent plant by a pedicel. The non-calcified gyrogonites, which are not seen in life position, are composed of six sinistrally spiralling cells and have six coronula cells arranged in a single layer around an apical pore.Because the oogonia of P. cranii have six sinistrally spiralling cells and an apical pore, Palaeonitella has been assigned to the Palaeocharaceae. The shape and form of the oogonia is reminiscent of the extant Chareae, but the morphology of the thalli is indicative of the Nitelleae. This suggests that P. cranii, although retaining some characteristics of the Nitelleae, has some of the characteristics of the Chareae, supporting existing molecular studies which place the Nitelleae at the base of the Characeae.Palaeonitella cranii inhabited the freshwater alkaline pools and streams which formed on sinter aprons created by hot spring activity. Extant charophytes exist in a similar environment (pH 8·66–8·9, temperature 25–30°C in summer) in pools and channels fed by hot springs in Yellowstone National Park, Wyoming, USA.

Early Life Exposure to Antibiotic Alters Energy Balance during Chronic High-Fat Feeding in Adult Male and Female Mice

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1999-P ◽  
Author(s):  
HYE LIM NOH ◽  
SUJIN SUK ◽  
RANDALL H. FRIEDLINE ◽  
KUNIKAZU INASHIMA ◽  
DUY A. TRAN ◽  
...  
Keyword(s):  
Energy Balance ◽  
Adult Male ◽  
Early Life ◽  
High Fat ◽  
Male And Female ◽  
Female Mice ◽  
Early Life Exposure ◽  
Fat Feeding

The Neurobiology of Pain

2019 ◽  
pp. 387-414
Author(s):  
Maria Fitzgerald ◽  
Michael W. Salter
Keyword(s):  
Early Life ◽  
Pain Perception ◽  
Long Term Effects ◽  
Male And Female ◽  
Functional Changes ◽  
Pain Pathways ◽  
Developmental Age ◽  
Short And Long Term ◽  
Age And Sex

The influence of development and sex on pain perception has long been recognized but only recently has it become clear that this is due to specific differences in underlying pain neurobiology. This chapter summarizes the evidence for mechanistic differences in male and female pain biology and for functional changes in pain pathways through infancy, adolescence, and adulthood. It describes how both developmental age and sex determine peripheral nociception, spinal and brainstem processing, brain networks, and neuroimmune pathways in pain. Finally, the chapter discusses emerging evidence for interactions between sex and development and the importance of sex in the short- and long-term effects of early life pain.

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