Research in Antarctica – challenging but necessary

Kellner, Alexander W. A.

doi:10.1590/0001-37652022202294s1

Cited by 2 publications

(2 citation statements)

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“…Since 2007, the project PALEOANTAR (organized by the Museu Nacional/Universidade Federal do Rio de Janeiro, Brazil) has been working in the Antarctic Peninsula to shed light on the diversification and evolutionary history of Antarctic ecosystems in the deep past (Lima et al 2021; Kellner 2022; Santos et al 2022), including studies on Mesozoic vertebrates (e.g., Kellner et al 2011, 2019; Brum et al 2022) and invertebrates (e.g., Pinheiro et al 2020; Videira-Santos 2020; Piovesan et al 2021). Here, we report on new ankylosaurian materials recovered from Antarctica during the PALEOANTAR expedition in 2015.…”

Section: Introductionmentioning

confidence: 99%

Ankylosaurian body armor function and evolution with insights from osteohistology and morphometrics of new specimens from the Late Cretaceous of Antarctica

Brum

Eleutério²,

Simões³

et al. 2023

Paleobiology

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The body armor of ankylosaurians is a unique morphological feature among dinosaurs. While ankylosaurian body armor has been studied for decades, paleohistological analyses have only started to uncover the details of its function. Yet there has been an overall bias toward sampling ankylosaurian remains from the Northern Hemisphere, with limited quantitative studies on the morphological and functional evolution of the osteoderms composing their body armor. Here, we describe new ankylosaurian materials recovered from the Late Cretaceous of Antarctica that, in combination with data compiled from the literature, reveal new insights into the evolution of the ankylosaurian body armor. Based on histological microstructure and phylogenetic results, the new Antarctic material can be assigned to Nodosauridae. This group shares the absence/poor development of their osteodermal basal cortex and highly ordered sets of orthogonal structural fibers in the superficial cortex. Our morphospace analyses indicate that large morphological diversity is observed among both nodosaurids and ankylosaurids, but osteoderms became more functionally specialized in late-diverging nodosaurids. Besides acting as effective protection against predation, osteoderms also exhibit highly ordered structural fibers in nodosaurids, enabling a decrease in cortical bone thickness (as in titanosaurs), which could have been co-opted for secondary functions, such as calcium remobilization for physiological balance. The latter may have played a key role in nodosaurid colonization of high-latitude environments, such as Antarctica and the Arctic Circle.

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Section: Introductionmentioning

confidence: 99%

Ankylosaurian body armor function and evolution with insights from osteohistology and morphometrics of new specimens from the Late Cretaceous of Antarctica

Brum

Eleutério²,

Simões³

et al. 2023

Paleobiology

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“…Research in Antarctica has been increasing worldwide with constant investment and collaboration among researchers from different countries (e.g., Sampaio 2022), resulting in projects with increasing complexity (e.g., Simões et al 2022). Despite the several challenges to developing studies in this region, there has been a steady increase of scientific activity in the area (e.g., Kellner 2022, Santos et al 2022, which includes the search for fossil vertebrates (e.g., Reguero et al 2022), including extinct birds. serpulid worms and molluscans (e.g., Olivero et al 1986, Crame & Luther 1997, Olivero 2012a, Raffi et al 2019), crustaceans (Pinheiro et al 2020), chondrichthyans (e.g., Otero et al 2014), osteichthyans (e.g., Richter & Ward 1990, plesiosaurs (e.g., Chatterjee & Small 1989, Kellner et al 2011, O'Gorman 2012, O'Gorman et al 2019, Brum et al 2022, mosasaurs (Martin et al 2002, Novas et al 2002a, Martin 2006, pterosaurs (Kellner et al 2019), and avian and non-avian dinosaurs (Chatterjee 1989, Noriega & Tambussi 1995, Case & Tambussi 1999, Case et al 2000, Case 2001, Cordes 2001, Novas et al 2002b, Clarke et al 2005, Chatterjee et al 2006, Tambussi & Acosta Hospitaleche 2007, Reguero et al 2013, Roberts et al 2014, Brum et al 2023.…”

Section: Introductionmentioning

confidence: 99%

The Cretaceous Neornithine record and new Vegaviidae specimens from the López de Bertodano Formation (Upper Maastrichthian) of Vega Island, Antarctic Peninsula

SOUZA,

BULAK,

SOARES

et al. 2023

An. Acad. Bras. Ciênc.

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A worldwide revision of the Cretaceous record of Neornithes (crown birds) revealed that unambiguous neornithine taxa are extremely scarce, with only a few showing diagnostic features to be confidently assigned to that group. Here we report two new neornithine specimens from Vega Island (López de Bertodano Formation). The first is a synsacrum (MN 7832-V) that shows a complex pattern of transversal diverticula intercepting the canalis synsacri, as in extant neornithines. Micro-CT scanning revealed a camerate pattern of trabeculae typical of neornithines. It further shows the oldest occurrence of lumbosacral canals in Neornithes, which are related to a balance sensing system acting in the control of walking and perching. The second specimen (MN 7833-V) is a distal portion of a tarsometatarsus sharing with Vegavis iaai a straight apical border of the crista plantaris lateralis. Osteohistologically the tarsometatarsus shows a thick and highly vascularized cortex that lacks any growth marks, resembling Polarornis gregorii.The cortex is osteosclerotic as in other extinct and extant diving neornithines. These new specimens increase the occurrences of the Cretaceous avian material recovered from the Upper Cretaceous strata of the James Ross Sub-Basin, suggesting that a Vegaviidaedominated avian assemblage was present in the Antarctic Peninsula during the upper Maastrichtian.

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Research in Antarctica – challenging but necessary

Cited by 2 publications

References 4 publications

Ankylosaurian body armor function and evolution with insights from osteohistology and morphometrics of new specimens from the Late Cretaceous of Antarctica

Ankylosaurian body armor function and evolution with insights from osteohistology and morphometrics of new specimens from the Late Cretaceous of Antarctica

The Cretaceous Neornithine record and new Vegaviidae specimens from the López de Bertodano Formation (Upper Maastrichthian) of Vega Island, Antarctic Peninsula

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