Behavioural impacts on the taphonomy of dragonflies and damselflies (Odonata) from the Lower Cretaceous Crato Formation, Brazil

2021 ◽  
Vol 4 (2) ◽  
pp. 141-155
Author(s):  
NATHAN T. BARLING ◽  
SAM W. HEADS ◽  
DAVID M. MARTILL
Keyword(s):  
Lower Cretaceous ◽  
Principal Coordinate Analysis ◽  
Physical Conditions ◽  
Fossil Insect ◽  
Body Components ◽  
Insect Fossils

The relative completeness of Odonata (dragonflies and damselflies) fossils from the Crato Formation is investigated and compared to other fossil insect groups from the same formation. Tagma completeness is measured as present, partial, or absent, with some additional subdivision of body components (head, thorax, limbs, individual wings, anterior and posterior abdomen). These data are statistically explored for trends using principal coordinate analysis. While no definitive clustering is identified, most Crato Formation Odonata fossils plot positively on coordinate two, whereas the majority of non-odonatan insect fossils plot negatively on this coordinate. This shows that the Crato Formation odonates are less complete compared to other insect groups from the same beds. Specimens preserved as isolated wings and those preserved with damaged or lost abdomens are identified as contributing to this difference. The causes of these differences are discussed, highlighting collection bias, predation, carcass scavenging, physical conditions of the palaeoenvironment, as well as the autecology of odonates.

Chemical and mineral comparison of fossil insect cuticles from Crato Konservat Lagerstätte, Lower Cretaceous of Brazil

2020 ◽  
Vol 46 (1) ◽  
pp. 61-76 ◽  
Author(s):  
Francisco Irineudo Bezerra ◽  
João H. da Silva ◽  
Emílio de Castro Miguel ◽  
Alexandre R. Paschoal ◽  
Daniel R. Nascimento ◽  
...  
Keyword(s):  
Lower Cretaceous ◽  
Fossil Insect

scholarly journals Taphonomy and Paleoecology of Fossil Insect Assemblages from Old Crow River (CRH-15) Northern Yukon Territory, Canada

2007 ◽  
Vol 37 (2) ◽  
pp. 147-157 ◽  
Author(s):  
Richard E. Morlan ◽  
John V. Matthews
Keyword(s):  
Yukon Territory ◽  
Single Site ◽  
Ecological Groups ◽  
Regional Environment ◽  
Fossil Insect ◽  
Different Types ◽  
Present Distribution ◽  
The Individual ◽  
Insect Fossils ◽  
Host Sediment

ABSTRACT The paleoenvironmental message delivered by any fossil assemblage is nearly always filtered to some degree by taphonomic and preservational biases. This paper discusses some of the types of biases that affect the composition of fossil Coleoptera (beetles) assemblages. Eight samples from a single site in the northern Yukon provide the raw data for the analysis. They represent different types of host sediments — ranging from autochthonous peats to organic rich alluvial sands. For each assemblage the authors noted the state of preservation of the fossils, counted the individual anatomical parts (pronota, heads, elytra) referred to each taxon and the number of articulated or partially articulated specimens, and sorted the fossils on the basis of predefined ecological groups. The resulting data were then examined statistically, and compared with paleoenvironmental conclusions derived by examination of the present distribution of the taxa in each assemblage. The content of the insect assemblages varies with the type of host sediment. Insect fossils from autochthonous sediments deliver a reliable local environmental signal. Allochthonous sediments, such as alluvium, might be expected to contain fossils that provide an integrated picture of the regional environment, but in the Yukon such samples are seriously overrep resented by Lepidophorus lineaticollis, a weevil that lives on or near sandy floodplains. Deviations in the representation of particular anatomical elements of L. lineaticollis from one sample to another warn of other more subtle taphonomic biases that may also skew the content of northern fossil insect assemblages.

scholarly journals X-ray micro-tomography of Carboniferous stem-Dictyoptera: new insights into early insects

2010 ◽  
Vol 6 (5) ◽  
pp. 699-702 ◽  
Author(s):  
Russell Garwood ◽  
Mark Sutton
Keyword(s):  
High Resolution ◽  
Wing Venation ◽  
X Ray ◽  
Rapid Movement ◽  
Fossil Insect ◽  
Stem Group ◽  
Mode Of Life ◽  
Micro Tomography ◽  
High Degree ◽  
Insect Fossils

Computer reconstructions of Archimylacris eggintoni , a Carboniferous stem-group dictyopteran (‘roachoid’), are presented. A siderite-hosted specimen was scanned using high-resolution X-ray microtomography (µCT), and a ‘virtual fossil’ was created with a resolution of 17.7 µm. This has revealed the morphology in great detail, including adhesive limb structures indicative of climbing and specializations for rapid movement. The antennae are filiform, and the mandibles are comparable to those of certain extant cockroaches, suggesting a similar generalist, saprophagous diet. The reconstruction reveals a high degree of specialization, and provides insights into the mode of life of these common Palaeozoic insects. Further µCT study of insect fossils has the potential to supplement wing venation with new characters, and hence improve fossil insect phylogenies.

scholarly journals IV.—On the Albian, or Gault, of Folkestone

1868 ◽  
Vol 5 (46) ◽  
pp. 163-171 ◽  
Author(s):  
C. E. De Rance
Keyword(s):  
Lower Cretaceous ◽  
Physical Conditions

From the proposition of Professor Forbes, that a species once extinct never reappears, it follows that when a species recurs, it must have existed elsewhere during the whole of the time occupied by the deposition of the strata between the deposits containing it. In viewing the distribution of species through the cheif stages of the Lower Cretaceous system, it appears that the same species reappear when there is a recurrence of the same or similar physical conditions,—the Neocomian and Albian clays having more species in common than the intervening Aptian; and the Aptian and Cenomanian sands, being more closely allied than the intervening Albian clay. An examination of the latter, at Folkestone, appears to allow of its being divided into eleven lithological stages or beds which have been more or less recognized by all geologists and fossil collectors who have visited the district. To these beds provisional names have been assigned expressive either of their colour, position, or characteristic fossils. But in tracing all the recurring species from their genesis in one stratum to their extinction in another, these beds are found to have no great palæontological value, but to resolve themselves into two groups divided by a junction bed, in the same way as the “junction bed” separates the Albian from the Upper Aptian. Beds I. to III. forming an Upper, beds V. to X. a Lower Albian, beds IV. and XI. being the two phosphate junction beds,

A new species of damsel-dragonfly (Odonata: Stenophlebiidae: Cretastenophlebia) from the Lower Cretaceous of the Jiuquan Basin, northwestern China

2016 ◽  
Vol 107 (2-3) ◽  
pp. 185-189 ◽  
Author(s):  
Daran Zheng ◽  
Haichun Zhang ◽  
Bo Wang ◽  
Su-Chin Chang
Keyword(s):  
New Species ◽  
Lower Cretaceous ◽  
Northwestern China ◽  
Wing Margin ◽  
Central Mongolia ◽  
Insect Fossils ◽  
A New Species ◽  
New Discovery

ABSTRACTAbundant insect fossils have been recorded from the Lower Cretaceous of the Jiuquan Basin, but very few odonatans have been recorded. In this paper, a new damsel-dragonfly, Cretastenophlebia jiuquanensis sp. nov., is described from the Lower Cretaceous Zhonggou Formation in the Hanxiagou outcrop, Jiuquan Basin, northwestern China. This is the second species of the genus Cretastenophlebia Fleck et al., 2003. Cretastenophlebia jiuquanensis sp. nov. differs from Cretastenophlebia mongolica Fleck et al., 2003 in the presence of a broad discoidal triangle, a basally straight IR1 and less cells along the posterior wing margin between IR2 and RP2. Cretastenophlebia has been previously reported from the Lower Cretaceous of Bon-Tsagaan, central Mongolia. The new discovery expands the record of Cretastenophlebia to the Jiuquan Basin in Albian.

First fossil insect from Lower Cretaceous Lebanese amber in Syria (Diptera: Ceratopogonidae)

2015 ◽  
Vol 54 ◽  
pp. 106-116 ◽  
Author(s):  
Joanna Choufani ◽  
Wafaa El-Halabi ◽  
Dany Azar ◽  
André Nel
Keyword(s):  
Lower Cretaceous ◽  
Fossil Insect

Influence of Magnetic Fields on Solar Hydrodynamics: Experimental Results

1977 ◽  
Vol 36 ◽  
pp. 143-180 ◽  
Author(s):  
J.O. Stenflo
Keyword(s):  
Solar Activity ◽  
Energy Balance ◽  
Magnetic Fields ◽  
Solar Atmosphere ◽  
General Problem ◽  
Solar Rotation ◽  
Active Regions ◽  
Physical Conditions ◽  
Dynamic Phenomena

It is well-known that solar activity is basically caused by the Interaction of magnetic fields with convection and solar rotation, resulting in a great variety of dynamic phenomena, like flares, surges, sunspots, prominences, etc. Many conferences have been devoted to solar activity, including the role of magnetic fields. Similar attention has not been paid to the role of magnetic fields for the overall dynamics and energy balance of the solar atmosphere, related to the general problem of chromospheric and coronal heating. To penetrate this problem we have to focus our attention more on the physical conditions in the ‘quiet’ regions than on the conspicuous phenomena in active regions.

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