Natural History Museum of Geneva

With a size of 51.2 × 7.2 km, the 10.9 ± 1.7 ka old Jiddat al Harasis 091 L5 chondrite strewn field is the largest known in Oman. It consists of more than 700 meteorites with a total mass of >4.5 tons from which the largest six stones of >100 kg to 1.5 tons make up two thirds of the total mass. Small stones are underrepresented, consistent with a fracturing behavior of a meteor with low shock level. Modeling yields that a bolide with 28 ± 12 tons (115 ± 15 cm radius) entered the atmosphere at a shallow angle of 22° ± 2° with a velocity of about 16 kms −1 . For ~16 s, it produced a spectacular meteor along a luminous path of ~200 km length. Mass mixing within the rather straight and narrow strewn field indicates a sequence of multiple fragmentations from below 50 km down to 7 km altitude. This can be resolved adopting a wind profile from nowadays winter season, as the weather patterns with alternating Monsoon and Passat winds in the region are rather well known and repeatable since the last ice age. The largest masses with 1447 and 842 kg, respectively, produced impact breccia consisting of limestone and meteorite fragments. According to the model, the biggest mass hit the ground at a velocity of 175 ms −1 and released an impact energy of 22 MJ, corresponding to 5.3 kg TNT. This may have produced an impact crater of ~1 m diameter which, however, is not preserved. Breccia found below a much smaller mass of 68 kg deserves an explanation beyond impact energy.

Palaeospondylus fossils are linked to hagfish, ostracoderms, jawed vertebrates, and tetrapods, reflecting uncertain phylogenetic placement. Recent studies on P. gunni and P. australis suggest phylogenetic relationships with Tetrapodomorpha and Chondrichthyes, respectively. Jawed vertebrates are characterized by three semicircular canals, with two in cyclostomes. Palaeospondylus exhibits three canals, aligning it more closely with jawed vertebrates. Only one otoconia (sacculus) has found in P. australis, whereas jawed vertebrates typically have at least two (utricle and saccule), while cyclostomes have only one otoconia. Osteichthyes have at least six sensory epithelia, while Cyclostomes have 3-4 sensory epithelia. P. australis appears to have around four sensory epithelia, which is intermediate and unique among jawed vertebrates, potentially representing a basal condition.

Aporocotyle is the second richest genus of fish blood flukes within the family Aporocotylidae. These cosmopolitan trematodes infect the heart, bulbus arteriosus, and blood vessels of marine fishes belonging to the orders Gadiformes, Ophidiiformes, Perciformes, Pleuronectiformes, and Scorpaeniformes. In this study, three species of Aporocotyle, i.e. A. argentinensis, A. mariachristinae, and A. ymakara, from teleost fishes collected in the San Matías Gulf, Patagonia, Argentina, are morphologically and genetically characterized. Re-examination of these blood flukes provided new detailed drawings, measurements, photomicrographs, confocal and scanning electron microscopy (SEM) images. Aporocotyle argentinensis is redescribed based on type-, voucher- and newly collected material from the bulbus arteriosus, heart and gill blood vessels of the Argentine hake Merluccius hubbsi from Argentina. We generated partial sequences for the large subunit of the nuclear ribosomal RNA (28S rRNA) and the mitochondrial cytochrome c oxidase subunit 1 (cox1) genes for A. argentinensis and A. ymakara and used these sequences to investigate the phylogenetic relationships of these blood flukes. Our morphological analyses highlighted the taxonomic importance of the distribution of tegumental spines, the extension of the posterior caeca, and the presence of a genital atrium to circumscribe and classify species of Aporocotyle. Phylogenetic analyses recovered A. mariachristinae and A. ymakara as closely related taxa and placed the new sequences of A. argentinensis in a clade together with previously published sequences of isolates identified as A. argentinensis from three hake species (Merluccius hubbsi, M. gayi and M. australis) from Argentina, Chile, Peru and the Falkland Islands. This study provides a comprehensive review of the diversity of Aporocotyle in the southwest Atlantic, contributing to a better understanding of the systematics and evolutionary history of these blood flukes.

With accelerating biodiversity loss, tracking both inter- and intraspecific diversity is critical, as within-species variation underpins population viability and adaptive potential. We developed a new multi-locus framework, and obtained an Orthoptera-specific marker panel targeting 398 nuclear loci plus the mitogenome and ribosomal DNA to assess species boundaries, population structure and intraspecific diversity. We applied this approach to 645 specimens covering all 105 Swiss Orthoptera species, sampled during the nationwide Red List update. This multi-locus dataset produced a well-supported phylogeny and resolved several taxonomic ambiguities with direct conservation relevance. We demonstrate its ability to identify fine-scale population structure and further illustrate its application to genetic diversity estimation. While species' IUCN threat levels were not correlated with genetic diversity, we found a significant negative association between genetic diversity and dependence on riparian habitats: river-bank specialists showed lower diversity, likely reflecting the severe fragmentation and alteration of these ecosystems. Our results demonstrate that the application of new molecular tools provides valuable, complementary insights not only for taxonomy but also for conservation assessments. The development and application of genetic monitoring frameworks, such as the one presented here, are highly valuable for promoting the inclusion of genetic diversity in future conservation assessments.

Abstract Flight loss, through its effect on the resulting dispersal capacity and gene flow, has been proposed as a driver of diversification. Ground beetles of the genus Calosoma are unique among the predominantly flightless Carabinae, as nearly half of the species retain flight-capability. Most flightless Calosoma occur in extreme, often isolated habitats such as montane ecosystems. Species in this genus provide an ideal system to investigate the impact of flight loss on diversification across geographical scales. Here, we focus on the flightless species Calosoma (Carabophanus) gestroi, which occurs at high elevations in the southern mountains surrounding the Great Rift Valley of Ethiopia. We investigate genetic differentiation among populations and the biogeographical history of this species across its geographical range using HyRAD-X data. Our results indicate that populations from different mountains form distinct clades, exhibiting both deep genetic differentiation and signatures of recent admixture. The combination of warmer Pliocene climatic conditions and the ongoing orogeny of the Ethiopian highlands promoted an ideal setup for complex cycles of population isolation and admixture. Warm periods drove genetic fixation on either side of the Great Rift Valley, whereas glacial oscillations across emerging sky islands in the Eastern Mountains facilitated genetic homogenization through cycles of allopatric isolation and secondary contact.