A historical vertebrate collection from the Middle Miocene of the Peruvian Amazon

The Miocene aquatic and terrestrial fossil record from western Amazonia constitute a clear evidence of the palaeoenvironmental diversity that prevailed in the area, prior to the establishment of the Amazon River drainage. During the Miocene, the region was characterized by a freshwater megawetland basin, influenced by episodic shallow-marine incursions. A fossil vertebrate collection from the middle Miocene strata of the Pebas Formation is here studied and described. This historical collection was recovered in 1912 along the banks of the Itaya River (Iquitos, Peru), during a scientific expedition led by two scientists of the University of Zurich, Hans Bluntschli and Bernhard Peyer. Our findings include a total of 34 taxa, including stingrays, bony fishes, turtles, snakes, crocodylians, and lizards. Fishes are the most abundant group in the assemblage (~ 23 taxa), including the first fossil record of the freshwater serrasalmids Serrasalmus, and Mylossoma, and the hemiodontid Hemiodus for the Pebas system, with the latter representing the first fossil be discovered for the entire Hemiodontidae. The presence of a representative of Colubroidea in the middle Miocene of Iquitos supports the hypothesis of arrival and dispersal of these snakes into South America earlier than previously expected. This fossil assemblage sheds light on the palaeoenvironments, and the geographical/temporal range of several aquatic/terrestrial lineages inhabiting the Amazonian region

A Pliocene-Pleistocene continental biota from Venezuela

The Pliocene-Pleistocene transition in the Neotropics is poorly understood despite the major climatic changes that occurred at the onset of the Quaternary. The San Gregorio Formation, the younger unit of the Urumaco Sequence, preserves a fauna that documents this critical transition. We report stingrays, freshwater bony fishes, amphibians, crocodiles, lizards, snakes, aquatic and terrestrial turtles, and mammals. A total of 49 taxa are reported from the Vergel Member (late Pliocene) and nine taxa from the Cocuiza Member (Early Pleistocene), with 28 and 18 taxa reported for the first time in the Urumaco sequence and Venezuela, respectively. Our findings include the first fossil record of the freshwater fishes Megaleporinus, Schizodon, Amblydoras, Scorpiodoras, and the pipesnake Anilius scytale, all from Pliocene strata. The late Pliocene and Early Pleistocene ages proposed here for the Vergel and Cocuiza members, respectively, are supported by their stratigraphic position, palynology, nannoplankton, and 86 Sr/ 88 Sr dating. Mammals from the Vergel Member are associated with the first major pulse of the Great American Biotic Interchange. In contrast to the dry conditions prevailing today, the San Gregorio Formation documents mixed open grassland/forest areas surrounding permanent freshwater systems, following the isolation of the northern South American basin from western Amazonia. These findings support the hypothesis that range contraction of many taxa to their current distribution in northern South America occurred rapidly during at least the last 1.5 million years

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified

Phylogenetic relationships of the South American Doradoidea (Ostariophysi: Siluriformes)

A phylogenetic analysis based on 311 morphological characters is presented for most species of the Doradidae, all genera of the Auchenipteridae, and representatives of 16 other catfish families. The hypothesis that was derived from the six most parsimonious trees support the monophyly of the South American Doradoidea (Doradidae plus Auchenipteridae), as well as the monophyly of the clade Doradoidea plus the African Mochokidae. In addition, the clade with Sisoroidea plus Aspredinidae was considered sister to Doradoidea plus Mochokidae. Within the Auchenipteridae, the results support the monophyly of the Centromochlinae and Auchenipterinae. The latter is composed of Tocantinsia, and four monophyletic units, two small with Asterophysusand Liosomadoras, and Pseudotatiaand Pseudauchenipterus, respectively, and two large ones with the remaining genera. Within the Doradidae, parsimony analysis recovered Wertheimeriaas sister to Kalyptodoras, composing a clade sister to all remaining doradids, which include Franciscodorasand two monophyletic groups: Astrodoradinae (plus Acanthodorasand Agamyxis) and Doradinae (new arrangement). Wertheimerinae, new subfamily, is described for Kalyptodoras and Wertheimeria. Doradinae is corroborated as monophyletic and composed of four groups, one including Centrochirand Platydoras, the other with the large-size species of doradids (except Oxydoras), another with Orinocodoras, Rhinodoras, and Rhynchodoras, and another with Oxydorasplus all the fimbriate-barbel doradids. Based on the results, the species of Opsodoras are included in Hemidoras; and Tenellus, new genus, is described to include Nemadoras trimaculatus, N. leporhinusand Nemadoras ternetzi. Due to conflicting hypotheses of the phylogenetic position of Acanthodoras, Agamyxis, and Franciscodoras, these are considered as incertae sedisin Doradidae. All suprageneric taxa of the Doradoidea are diagnosed based on synapomorphic morphological characteristics