Anacoracid sharks and calcareous nannofossil stratigraphy of the mid-Cretaceous ‘upper’ Gearle Siltstone and Haycock Marl in the lower Murchison River area,Western Australia

Siversson, M., Cook, T.D., Ryan, H.E., Watkins, D.K., Tatarnic, N.J., Downes, P.J. & Newbrey, M.G. May 2018. Anacoracid sharks and calcareous nannofossil stratigraphy of the mid-Cretaceous Gearle Siltstone and Haycock Marl in the lower Murchison River area, Western Australia. Alcheringa XX, XX–XX.

Extensive bulk sampling over the past 20 years and greatly improved stratigraphic control permitted a meaningful revision of previously described anacoracid sharks from the ‘upper’ Gearle Siltstone and lower Haycock Marl in the lower Murchison River area, Western Australia. Isolated teeth of anacoracids are rare in the lower three (Beds 1–3) of four stratigraphic units of the ‘upper’ Gearle Siltstone but relatively common in the uppermost layer (Bed 4) and in the lower part of the overlying Haycock Marl. On the basis of calcareous nannofossils, Beds 1 and 2 of the ‘upper’ Gearle Siltstone can be placed in the uppermost upper Albian calcareous nannofossil Subzone CC9b whereas Bed 3 can be referred to the lowermost Cenomanian CC9c Subzone. Bed 1 yielded fragments of strongly serrated anacoracid teeth as well as a single, smooth-edged tooth. The samples from Beds 2 and 3 contained a few small fragments of serrated anacoracid teeth. Bed 4 is barren of calcareous nannofossils but the presence of a dentally advanced tooth of the cosmopolitan lamniform genus Cretoxyrhina in combination with the age of the overlying Haycock Marl indicate deposition within the younger half of the Cenomanian. The unit produced teeth of two anacoracids; Squalicorax acutus sp. nov. and S. bazzii sp. nov. The basal, laminated part of the Haycock Marl is placed in the uppermost upper Cenomanian part of CC10b. It yielded Squalicorax mutabilis sp. nov. and S. aff. S. bernardezi. Exceptionally well-preserved teeth of the former species span a 5:1 size ratio range for teeth of comparable jaw position. The teeth reveal strong ontogenetic heterodonty with a large increase in the relative size of the main cusp with age and the transition from a vertical distal heel of the crown in very young juveniles to a sub-horizontal, well demarcated heel in ‘adult’ teeth. An isolated phosphatic lens in the lower part of the Haycock Marl produced calcareous nannofossils indicative of the CC10b SubZone, most likely the lowermost lower Turonian part. It contains teeth of Squalicorax mutabilis sp. nov., S. aff. S. bernardezi, and S. sp. C.

Mikael Siversson* [mikael.siversson@museum.wa.gov.au], Helen E. Ryan [helen.ryan@museum.wa.gov.au] and Peter Downes [peter.downes@museum.wa.gov.au] Department of Earth and Planetary Sciences, Western Australian Museum, 49 Kew Street, Welshpool, Western Australia 6106, Australia; David K. Watkins [dwatkins@unl.edu] Department of Earth and Atmospheric Sciences, University of Nebraska, Lincoln, NE 68588, USA; Todd D. Cook [tdc15@psu.edu] School of Science, Penn State Behrend, 4205 College Drive, Erie, PA 16563, USA; Nikolai J. Tatarnic? [nikolai.tatarnic@museum.wa.gov.au] Department of Terrestrial Zoology, Western Australian Museum, 49 Kew Street, Welshpool, Western Australia 6106, Australia; Michael G. Newbrey? [newbrey_michael@columbusstate.edu] Department of Biology, Columbus State University, Columbus, GA 31907-5645, USA. *Also affiliated with: School of Molecular and Life Sciences, Curtin University, Kent Street, Bentley, WA 6102, Australia. ?Also affiliated with: Centre for Evolutionary Biology, University of Western Australia, Crawley, Western Australia 6009. ?Also affiliated with: Canadian Fossil Discovery Centre, 111-B Gilmour Street, Morden, Manitoba R6 M 1N9, Canada.

http://zoobank.org/urn:lsid:zoobank.org:pub:97D5131F-C0D5-4A7E-9C9A-0FDF13BFCBBB

http://zoobank.org/urn:lsid:zoobank.org:act:5977DCC2-355C-4732-8B0A-4BD0EABBA8DE

http://zoobank.org/urn:lsid:zoobank.org:act:2D7C4147-B756-4434-847A-B0C1C6D167DF

http://zoobank.org/urn:lsid:zoobank.org:act:33F3B55E-41E0-45B3-8296-A3B95C17B41D     

Childhoods past and present: anxiety and idyll in reminiscences of childhood outdoor play and contemporary parenting practices

ABSTRACT

Outdoor play is considered an essential aspect of a ‘proper childhood’. However, unsupervised outside play is declining, a decline attributed to parental anxieties about children’s safety. However what drives these anxieties and how this impacts on contemporary outdoor play is less clear. Our paper seeks to explore this through an analysis of adult narratives generated through digital map-making and forum discussion about where they played as children and where they would allow a child to play unsupervised now. Our analysis explores the nature of these narratives and pivotal moments in which adults articulated the disconnect between their own recollections of idyllic spatial freedom and the spatial restrictions they place on contemporary children. This offers a rich understanding of how parents navigate conflicting cultural imperatives on risk-avoidance and children’s rights to a ‘good’ childhood.     

Confirmation of the presence of Mycobacterium tuberculosis complex‐specific DNA in three archaeological specimens

This journal published the first reported identification of Mycobacterium tuberculosis complex (MTB) DNA in ancient human remains but concerns were raised about the article two years after publication. These were based on methodology which, in the field of ancient DNA, was still developing. Here we present a re‐examination of the 1993 research conducted on three specimens which exhibited palaeopathologies indicative of tuberculosis. The specimens were: an ulna from pre‐European‐contact Borneo, a spine from Byzantine Turkey, and a lumbar‐sacral spine from 17th century Scotland. There was insufficient material to permit re‐examination of all of the original samples. The earlier results were confirmed in two independent laboratories using different methodologies. MTB DNA complex‐specific DNA amplicons were obtained, and sequenced in both laboratories, in a re‐analysis of samples which supported the earlier findings. Copyright © 2002 John Wiley & Sons, Ltd.