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Université de Fribourg

Cranial osteology of the early cretaceous turtle Pleurosternon bullockii (paracryptodira: pleurosternidae)

Evers, Serjoscha W. ; Rollot, Yann ; Joyce, Walter G.

In: PeerJ, 2020, vol. 8, p. e9454

Pleurosternon bullockii is a turtle from the Early Cretaceous of Europe known from numerous postcranial remains. Only one skull has so far been referred to the species. Pleurosternon bullockii belongs to a group of turtles called pleurosternids, which is thought to include several poorly known taxa from the Late Jurassic and Early Cretaceous of Europe and North America. Pleurosternids and...

Université de Fribourg

The last surviving Thalassochelydia — A new turtle cranium from the Early Cretaceous of the Purbeck Group (Dorset, UK)

Anquetin, Jérémy ; André, Charlotte

In: PaleorXiv, 2020, p. 7pa5c

Background. The mostly Berriasian (Early Cretaceous) Purbeck Group of southern England has produced a rich turtle fauna dominated by the freshwater paracryptodires Pleurosternon bullockii and Dorsetochelys typocardium. Each of these species is known by numerous relatively complete shells and by a single cranium. The two other turtles found in the Purbeck Group (Hylaeochelys belli, a species of...

Université de Fribourg

A new species of baenid turtle from the Early Cretaceous Lakota Formation of South Dakota

Joyce, Walter G. ; Rollot, Yann ; Cifelli, Richard L.

In: Fossil Record, 2020, vol. 23, no. 1, p. 1–13

Baenidae is a clade of paracryptodiran turtles known from the late Early Cretaceous to Eocene of North America. The proposed sister-group relationship of Baenidae to Pleurosternidae, a group of turtles known from sediments dated as early as the Late Jurassic, suggests a ghost lineage that crosses the early Early Cretaceous. We here document a new species of paracryptodiran turtle, Lakotemys...

Université de Fribourg

Photic stress on coral reefs in the Maldives: The Amphistegina bleaching index

Stainbank, Stephanie ; Spezzaferri, Silvia ; Beccari, Valentina ; Hallock, Pamela ; Adams, Arthur ; Angeloz, Aurelie ; Basso, Daniela ; Caragnano, Annalisa ; Piero, Nicolo Del ; Dietsche, Patrick ; Eymard, Ines ; Farley, Nicholas ; Fau, Marine ; Foubert, Anneleen ; Lauper, Bruno ; Lehmann, Anael ; Maillet, Marine ; Negga, Haileyesus ; Ordonez, Luis ; Peyrotty, Giovan ; Rime, Valentin ; Rüggeberg, Andres ; Schoellhorn, Iris ; Vimpere, Lucas

In: Ecological Indicators, 2020, vol. 113, p. 106257

The Amphistegina Bleaching Index (ABI) was applied to three Maldivian reefs in the Rasdhoo and North Ari Atolls in 2018, during normal sea surface temperature conditions. This dataset was then compared with a 2015, pre-coral bleaching study. The results provide a context for the verification and application of the ABI in outlining the photo-inhibitory stress status of coral reefs outside of...

Université de Fribourg

Embryonic photosynthesis affects post-germination plant growth

Sela, Ayala ; Piskurewicz, Urszula ; Megies, Christian ; Mène-Saffrané, Laurent ; Finazzi, Giovanni ; Lopez-Molina, Luis

In: Plant Physiology, 2020, vol. 182, no. 4, p. 2166–2181

Photosynthesis is the fundamental process fueling plant vegetative growth and development. The progeny of plants relies on maternal photosynthesis, via food reserves in the seed, to supply the necessary energy for seed germination and early seedling establishment. Intriguingly, before seed maturation, Arabidopsis (Arabidopsis thaliana) embryos are also photosynthetically active, the...

Université de Fribourg

Hormonal modulation of larval begging and growth in the burying beetle Nicrophorus vespilloides

Crook, Tara C. ; Flatt, Thomas ; Smiseth, Per T.

In: Animal behaviour, 2008, vol. 75, no. 1, p. 71-77

Recent studies on birds show that two steroid hormones, testosterone and corticosterone, stimulate nestling begging and growth. Here, we seek to investigate whether juvenile hormone, a major regulatory insect hormone, has similar effects on larval begging and growth in insects. To this end, we experimentally elevated larval juvenile hormone levels by topical application of methoprene, a potent...

Université de Fribourg

Juvenile and Steroid Hormones in Drosophila melanogaster Longevity

Flatt, Thomas ; Tu, Meng-Ping ; Tatar, Marc

In: The Handbook of the Biology of Aging, 2006, p. 415-448

This chapter reviews hormonal effects on aging in Drosophila melanogaster. The insect juvenile hormone (JH) is a sesquiterpenoid compound produced by the corpora allata (CA), a pair of endocrine glands with nervous connections to the brain. In pre- adult development and metamorphosis, JH functions as a "status quo" hormone, allowing continued growth after ecdysteroid-induced molting....

Université de Fribourg

Hormonal pleiotropy and the juvenile hormone regulation of Drosophila development and life history

Flatt, Thomas ; Tu, Meng-Ping ; Tatar, Marc

In: BioEssays, 2005, vol. 27, no. 10, p. 999-1010

Understandinghowtraits are integrated at the organismal level remains a fundamental problem at the interface of developmental and evolutionary biology. Hormones, regulatory signaling molecules that coordinate multiple developmental and physiological processes, are major determinants underlying phenotypic integration. The probably best example for this is the lipid-like juvenile hormone (JH)...