A new extinct species of Margarobyas (Strigiformes) and the evolutionary history of the endemic Cuban bare-legged owl (M. lawrencii)

Author(s):  
Nikita V. Zelenkov ◽  
Soraida F. González
2015 ◽  
Vol 29 (2) ◽  
pp. 191 ◽  
Author(s):  
James K. Liebherr ◽  
Nick Porch

A late Holocene but prehistoric carabid beetle fauna from the lowland Makauwahi Cave, Kauai, is characterised. Seven extinct species – Blackburnia burneyi, B. cryptipes, B. godzilla, B. menehune, B. mothra, B. ovata and B. rugosa, spp. nov. (tribe Platynini) – represent the first Hawaiian insect species to be newly described from subfossil specimens. Four extant Blackburnia spp. – B. aterrima (Sharp), B. bryophila Liebherr, B. pavida (Sharp), and B. posticata (Sharp) – and three extant species of tribe Bembidiini – Bembidion ignicola Blackburn, B. pacificum Sharp and Tachys oahuensis Blackburn – are also represented. All subfossil fragments are disarticulated, with physical dimensions and cladistic analysis used to associate the major somites – head, prothorax and elytra – for description of the new species. The seven new Makauwahi Cave species support recognition of a lowland area of endemism adjoining Haupu, a low-stature 700 m elevation ridgeline in southern Kauai. Four of the extinct Blackburnia are adelphotaxa to extant species currently found at higher elevations in Kauai. Addition of these lowland specialists to the phylogenetic hypothesis undercuts applicability of the taxon cycle for interpreting evolutionary history of these taxa. Two of the extinct species are Kauai representatives in clades that subsequently colonised younger Hawaiian Islands, enhancing support for the progressive biogeographic colonisation of the archipelago by this lineage. And three of the extinct Blackburnia species comprised larger beetles than those of any extant Kauai Blackburnia, consistent with the evolution of island gigantism in the lowland habitats of Kauai.


Author(s):  
Alan Cannell

Three genera of very large volant birds existed for most of the Pliocene: the Pelagornithidae seabirds; the large North American Teratornithidae and the stork Leptoptilos falconeri in Africa and Asia. All became extinct around 3 Ma. The reasons for their demise are puzzling, as the Pelagornithidae had a world-wide evolutionary history of more than 50 Ma, smaller teratorns were still extant in the Holocene and smaller stork species are still globally extant. Extant large birds have a common critical takeoff airspeed suggesting a biomechanical limit in terms of power, risk and launch speed, and simulations of the flight of these extinct species suggest that at 1 bar they would have exceeded this value. Estimates for the Late Pliocene atmospheric density are derived from marine and terrestrial isotopes as well as resin chemistry, both approaches suggesting a value of about 1.2 bar, which drops to present levels during the period 3.3 to 2.6 Ma, thus a loss in atmospheric density may have caused biomechanical and ecological stress contributing to their extinction and/or development of smaller forms. This hypothesis is examined in terms of a possible mechanism of atmospheric mass loss and how this would be seen in the geological record. At 1.2 bar all the extinct species present takeoff airspeeds similar to large extant volant birds and which match the expected power and kinetic energy levels.


2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.


2017 ◽  
Author(s):  
James C. Lamsdell ◽  
◽  
Melanie J. Hopkins

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