All post- Cambrian ichnospecies of Psammichnites Torell, 1870 belong to Olivellites Fenton and Fenton, 1937a

2021 ◽  
pp. SP522-2021-102
Author(s):  
Pablo J. Pazos ◽  
Carolina Gutiérrez

AbstractThe ichnogenus Psammichnites herein restricted to Psammichnites gigas is based on comparison of morphology, feeding behaviour, contrast between the burrows and the host rock and possible producers. The record of siphonal activity as a “snorkel device” is discussed. The diagnosis of the ichnogenus Olivellites now is amended and includes all the records of Psammichnites in the post-Cambrian. Olivellites is now documented in successions other than the classical tidal flat deposits facies of the Carboniferous of the USA. We propose that the producer of Olivellites was an animal with capacity for displacement to different shallow infaunal levels for different feeding strategies. An interpretation of detritus feeding behavior with sediment displacement (pasichnia) is favoured here. The producer of Olivellites was likely to have been a bivalved mollusc that evolved after the Late Ordovician mass extinction. It was euryhaline and lived in a broad bathymetric range, and is recorded in temperate to glacially related successions. The material of Olivellites implexus from western Argentina is the youngest record of the ichnogegenus from Western Gondwana.

Author(s):  
Kristina D Lowe ◽  
Mark A Lott ◽  
Chad D Jensen

Abstract Objective  This study evaluated associations between parent–child connectedness and communication, parent feeding behaviors (restriction, pressure to eat, and monitoring), and age- and sex-standardized child body mass index (zBMI) in a sample of pre-adolescent children aged 8–12 years. Methods  A community sample of three hundred and eight child–parent dyads completed measures of communication and connectedness. Parents completed a feeding behavior measure and children were weighed and their height was measured. We examined whether parental feeding behaviors and parent–child communication and connectedness predicted child zBMI and whether parental feeding behaviors moderated the association between parent–child communication and connectedness and child zBMI. Results  Feeding restriction was positively associated with zBMI, while both pressure to eat and food monitoring exhibited negative associations with zBMI. Child-reported communication was inversely associated with zBMI and parental pressure to eat moderated this association such that lower pressure to eat predicted a stronger association between communication and zBMI. Conclusions  These findings are consistent with previous research suggesting that parent feeding strategies and parent–child communication are important contributors to child weight status. This study also provides preliminary evidence suggesting that adaptive parent–child communication is associated with lower body mass when parents avoid pressuring their child to eat. Our study provides an important extension of this body of research into middle childhood, a relatively understudied developmental stage.


2021 ◽  
pp. 1-27
Author(s):  
Sofia Pereira ◽  
Jorge Colmenar ◽  
Jan Mortier ◽  
Jan Vanmeirhaeghe ◽  
Jacques Verniers ◽  
...  

Abstract The end-Ordovician mass extinction, linked to a major glaciation, led to deep changes in Hirnantian–Rhuddanian biotas. The Hirnantia Fauna, the first of two Hirnantian survival brachiopod-dominated communities, characterizes the lower–mid Hirnantian deposits globally, and its distribution is essential to understand how the extinction took place. In this paper, we describe, illustrate, and discuss the first macrofossiliferous Hirnantia Fauna assemblage from Belgium, occurring in the Tihange Member of the Fosses Formation at Tihange (Huy), within the Central Condroz Inlier. Six fossiliferous beds have yielded a low-diversity, brachiopod-dominated association. In addition to the brachiopods (Eostropheodonta hirnantensis, Plectothyrella crassicosta, Hirnantia sp., and Trucizetina? sp.), one trilobite (Mucronaspis sp.), four pelmatozoans (Xenocrinus sp., Cyclocharax [col.] paucicrenulatus, Conspectocrinus [col.] celticus, and Pentagonocyclicus [col.] sp.), three graptolites (Cystograptus ancestralis, Normalograptus normalis, and ?Metabolograptus sp.), together with indeterminate machaeridians and bryozoans were identified. The graptolite assemblage, from the Akidograptus ascensus-Parakidograptus acuminatus Biozone, indicates an early Rhuddanian (Silurian) age, and thus, an unexpectedly late occurrence of a typical Hirnantia Fauna. This Belgian association may represent an additional example of relict Hirnantia Fauna in the Silurian, sharing characteristics with the only other known from Rhuddanian rocks at Yewdale Beck (Lake District, England), although reworking has not been completely ruled out. The survival of these Hirnantian taxa into the Silurian might be linked to delayed post-glacial effects of rising temperature and sea-level, which may have favored the establishment of refugia in these two particular regions that were paleogeographically close during the Late Ordovician–early Silurian.


2016 ◽  
Vol 90 (6) ◽  
pp. 1138-1147 ◽  
Author(s):  
William I. Ausich ◽  
Mark A. Wilson

AbstractRhuddanian crinoid faunas are poorly known globally, making this new fauna from the Hilliste Formation of western Estonian especially significant. The Hilliste fauna is the oldest Silurian fauna known from the Baltica paleocontinent, thus this is the first example of the crinoid recovery fauna after the Late Ordovician mass extinction. Hiiumaacrinus vinni n. gen. n. sp., Protaxocrinus estoniensis n. sp., Eomyelodactylus sp., calceocrinids, and five holdfast types are reported here. Although the fauna has relatively few taxa, it is among the most diverse Rhuddanian faunas known. Similar to other Rhuddanian crinoid faunas elsewhere, the Hilliste crinoid fauna contains crinoids belonging the Dimerocrinitidae, Taxocrinidae, Calceocrinidae, and Myelodactylidae; most elements of the new fauna are quite small, perhaps indicative of the Lilliput Effect.


Geology ◽  
2018 ◽  
Vol 46 (6) ◽  
pp. 535-538 ◽  
Author(s):  
Caineng Zou ◽  
Zhen Qiu ◽  
Simon W. Poulton ◽  
Dazhong Dong ◽  
Hongyan Wang ◽  
...  

1996 ◽  
Vol 1996 ◽  
pp. 78-78
Author(s):  
N.B. Prescott ◽  
T.T.F. Mottram ◽  
A.J.F. Webster

An automatic milking system (AMS) has the potential to milk cows when the cow chooses. However cows must attend the system at an appropriate frequency. The provision of food in the AMS is a robust, way of luring cows into the system. The system can be arranged such that the cows have to visit the AMS to access food in the exit area the other side. Here they can be fed forage or concentrate. It has been shown that feeding cows forage as a lure can result in modified forage feeding behaviour, and this may be to the detriment of the cows (Winter, 1993, Ketelaar-de-Lauwere, 1992). Feeding concentrate in the exit area may be an alternative design if the level of attendance generated is high enough. Cows can also be fed concentrate in the milking stall of the AMS. The aim of this experiment was to compare die effects of feeding forage or concentrate in the exit area and the effect of feeding or not feeding concentrate in the milking stall on attendances, and lying and feeding behaviour.


1997 ◽  
Vol 132 (1-4) ◽  
pp. 195-210 ◽  
Author(s):  
James D Marshall ◽  
Patrick J Brenchley ◽  
Paul Mason ◽  
George A Wolff ◽  
Ricardo A Astini ◽  
...  

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