The genus Breviturma, a group of brittle stars inhabiting intertidal and shallow subtidal zones, includes eight recognized species distributed mainly across the Indo-West Pacific. This study describes a new species, Breviturma securis sp. nov., from Taiwan. The new species is distinguishable from its congeners through both morphological and molecular evidence, including disc granule density, arm spine sequences, and distinctive color patterns on the dorsal disc and dorsal arm plates. Phylogenetic analyses based on 16S rRNA and COI genes support its unique status, revealing interspecific divergence distances of 18.27–26.66% between B. securis and other congeners in the Indo-West Pacific. Based on the distribution patterns of its congeners, B. securis is expected to be widely distributed in other regions of the Indo-West Pacific. A newly recorded species, Breviturma krohi (Stöhr, Boissin & Hoareau, 2013), from Taiwan is also reported.

Keywords: Breviturma securis sp. nov., Breviturma krohi, East Asia, 16S rDNA, cytochrome c oxidase subunit I (COI)

Kai Chang and Hsi-Te Shih. 2025. Description of A New brittle star of the Genus Breviturma (Ophiuroidea: Ophiocomidae), with a new record from Taiwan. European Journal of Taxonomy. 997(1); 28–50. DOI: doi.org/10.5852/ejt.2025.997.2919

Eutyrannosaurians were large predatory dinosaurs that dominated Asian and North American terrestrial faunas in latest Cretaceous times. These apex predators arose from smaller-bodied tyrannosauroids during the ‘middle’ Cretaceous that are poorly known owing to the paucity of fossil material. Here we report on a new tyrannosauroid, Khankhuuluu mongoliensis gen. et sp. nov., from lower Upper Cretaceous deposits of Mongolia that provides a new perspective on eutyrannosaurian origins and evolution. Phylogenetic analyses recover Khankhuuluu immediately outside Eutyrannosauria and recover the massive, deep-snouted Tyrannosaurini and the smaller, gracile, shallow-snouted Alioramini as highly derived eutyrannosaurian sister clades. Khankhuuluu and the late-diverging Alioramini independently share features related to a shallow skull and gracile build with juvenile eutyrannosaurians, reinforcing the key role heterochrony had in eutyrannosaurian evolution. Although eutyrannosaurians were mainly influenced by peramorphosis or accelerated growth, Alioramini is revealed as a derived lineage that retained immature features through paedomorphosis and is not a more basal lineage as widely accepted. Our results reveal that Asian tyrannosauroids (similar to Khankhuuluu) dispersed to North America, giving rise to Eutyrannosauria in the mid-Late Cretaceous. Eutyrannosauria diversified and remained exclusively in North America until a single dispersal to Asia in the latest Cretaceous that established Alioramini and Tyrannosaurini. Stark morphological differences between Alioramini and Tyrannosaurini probably evolved due to divergent heterochronic trends—paedomorphosis versus peramorphosis, respectively—allowing them to coexist in Asia and occupy different ecological niches.

• New track-bearing surfaces are found in the Chacarilla Fm. in Quebrada des Arca.

• Five morphotypes: one of sauropod and four for different size theropod tracks are defined.

• Huge theropod tracks have been found and identified.

We report diverse dinosaur tracks from siltstone to fine-grained sandstone facies of the Chacarilla Formation, Quebrada de Arcas of northeast Chile. Track-bearing surfaces were studied using 3D modelling and false-colour depth maps, derived from UAV photographs. Five morphotypes are identified based on morphology and morphometric criteria. Morphotype I comprises rounded tracks with a consistent narrow-gauge and resembles the sauropod ichnogenus, Parabrontopodus; diplodocids or titanosaurids are probable trackmakers. Morphotype II is assigned to the theropod ichnotaxon Abelichnus astigerrae and comprises some of the largest theropod tracks ever recorded from South America with a maximum footprint length of 51 cm; the trackmaker was most likely a large carcharodontosaurid, such as Giganotosaurus carolinii. Morphotype III is an indeterminate theropod track, which shows a distinctive and prominent metatarsal impression, but does not closely match any ichnotaxon although it bears some morphometrical affinity to Changpeipus carbonicus. The Morphotypes IV and V both belong to small-sized theropod trackmakers, and resemble Grallatoridae and Kayentapus-like forms, respectively. Additional theropod material cannot be assigned to specific morphotypes or trackmakers, due to poor preservation. Our findings show the existence of three distinct size classes (small, medium and large) of theropod morphotypes and point to a high ichnodiversity at the Jurassic-Cretaceous transition in the subtropical arid environments of Gondwana.

Keywords: Dinosaur tracks, Abelichnus astigerrae, Chacarilla Formation, Gondwana, Jurassic-Cretaceous boundary

Aster mayangheense Z.Li (Asteraceae, Astereae), a new species from Guizhou, China, is described and illustrated here. Morphological and molecular analyses based on nuclear ribosomal DNA internal transcribed spacer (nrDNA ITS) confirm its distinct status. The species is morphologically similar to A. saxicola, but differs by its falcate, adaxially shiny upper leaves 3.5–5.0 × 0.8–2.0 cm with long-acuminate to caudate apices (versus oblong-lanceolate to lanceolate leaves in A. saxicola); 5-seriate, abaxially red-purple phyllaries (versus 3–5-seriate with purple-tipped phyllaries); and fewer florets (7–12 ray florets and 5–9 disc florets versus 9–14 ray florets and 10–18 disc florets). Phylogenetic analysis strongly supports its distinctness, with four samples forming a monophyletic clade (PP = 1.00, BS = 100%) nested within Aster.

Key words: Aster, morphology, molecular phylogeny, new taxon