Understanding the underlying mechanisms that have generated striking biodiversity inhabiting deep-sea ecosystems remains a challenge in evolutionary biology. Here, we addressed this topic by studying macroevolutionary dynamics shaped diversification of squaliform sharks, an iconic clade vertebrates. Using phylogenetic comparative methods and fossil-based Bayesian estimates, both at species level, combined fossil record data with molecular phylogenies to provide quantitative framework for...

Significance Many lineages increase in diversity through time, and some of them eventually decline get replaced. The causes such remain elusive are especially difficult to understand over a long-time scale global distribution. Relying on unprecedented species-level fossil datasets spanning the last 140 million years, we investigated wax wane mackerel sharks (Lamniformes), including great white shark. We find that both temperature competition with ecologically similar members their sister...

The question why non-avian dinosaurs went extinct 66 million years ago (Ma) remains unresolved because of the coarseness fossil record. A sudden extinction caused by an asteroid is most accepted hypothesis but it debated whether were in decline or not before impact. We analyse speciation-extinction dynamics for six key dinosaur families, and find a across dinosaurs, where diversification shifted to declining-diversity pattern ~76 Ma. investigate influence ecological physical factors, that...

The Cretaceous-Paleogene event was the last mass extinction event, yet its impact and long-term effects on species-level marine vertebrate diversity remain largely uncharacterized. We quantified elasmobranch (sharks, skates, rays) speciation, extinction, ecological change resulting from end-Cretaceous using >3200 fossil occurrences 675 species spanning Late Cretaceous-Paleocene interval at global scale. Elasmobranchs declined by >62% boundary did not fully recover in Paleocene. triggered a...

Background Modern selachians and their supposed sister group (hybodont sharks) have a long successful evolutionary history. Yet, although selachian remains are considered relatively common in the fossil record comparison with other marine vertebrates, little is known about quality of record. Similarly, only few works based on specific time intervals attempted to identify major events that marked history this group. Methodology/Principal Findings Phylogenetic hypotheses concerning modern...

The exact affinities of the fossil teeth attributed to devilrays (mobulids) are critical for resolving debated origin these giant pelagic rays amongst Myliobatiformes and timing their evolution toward planktivory. We performed first detailed comparative description belonging most living mobulids. Based on a survey devilrays, three dental morphologies newly identified as cobblestone tooth plates, comb-like teeth, peg-like teeth. In addition, all extinct mobulid species reviewed with comments...

Abstract Bulk-sampling of 22 phosphatic horizons from the Upper Cretaceous northern France and UK has yielded very rich selachian faunas dominated by shark taxa. These samples, collected Cenomanian to Campanian Chalks one glauconitic sediment, allow identification numerous new taxa, improve our knowledge European Late assemblages, with a special focus on small minute remains that were previously overlooked. Among 96 taxa described here, 18 species four genera are newly described:...

Abstract Estimating deep-time species-level diversification processes remains challenging. Both the fossil record and molecular phylogenies allow estimation of speciation extinction rates, but each type data may still provide an incomplete picture dynamics. Here, we combine palaeontological (fossil occurrences) neontological (molecular phylogenies) to estimate diversity dynamics through process-based birth–death models for Carcharhiniformes, most speciose shark order today. Despite their...

Since its usage by Darwin in 1859, the concept of 'living fossil' has undergone multiple definitions and been much discussed criticized. Soon after discovery 1938, coelacanth Latimeria was regarded as iconic example a fossil'. Several morphological studies have shown that lineage (Actinistia) not displayed critical transformation during evolutionary history molecular revealed low substitution rate for Latimeria, indicating slow genetic evolution. This statement, however, recently questioned...

Enameloid is a hard mineralized tissue covering chondrichthyan and actinopterygian teeth. Over the past 40 years, it has been extensively studied in various extinct extant sharks, leading to broad use of microstructural characters differentiate between hybodont neoselachian However, taxic diversity disproportionately high compared number taxa explored for enameloid microstructure, generalization these few observations whole group problematic. Indeed, many other groups, particular modern rays...

Estimating how traits evolved and impacted diversification across the tree of life represents a critical topic in ecology evolution. Although there has been considerable research comparative biology, large parts remain underexplored. Sharks are an iconic clade marine vertebrates, key components ecosystems since early Mesozoic. However, few studies have addressed or whether they their extant diversity patterns. Our study aimed to fill this gap by reconstructing largest time-calibrated...

AbstractThe first shark from the early Late Cretaceous Konservat Lagerstätte of Agoult (south-eastern Morocco) is described. The specimen consists anterior part an articulated skeleton including cephalic and branchial regions, vertebrae one pectoral fin. well-preserved dentition this indicates that it corresponds to fossil lamniform originally described as Odontaspis amonensis Cappetta & Case, Citation1975, a purported odontaspidid species unclear affinities. new material provides crucial...

Abstract Fishes are characterized by their capacity to occupy all aquatic environments and amazing range of size morphology. While it is known that habitat influenced the diversity dynamics fish clades, studies on environmental colonization events through evolutionary history ray‐finned fishes have yielded conflicting results as origin modern clades preferential directions shifts. The effects over morphological evolution such body remain poorly in vertebrates. However, more frequently...

Elasmobranchii is a clade of chondrichthyans (cartilaginous fishes) that comprises sharks, skates and rays represented today by approximately 1,200 species. Chondrichthyans have long evolutionary history dating back to the Late Ordovician (ca. 450 million years ago [Mya]) based on isolated dermal denticles (Janvier 1996). Other remains such as articulated skeletons teeth are known from Lower Devonian 410 Mya: Mader 1986; Miller et al. 2003). The fossil record modern elasmobranchs...

Abstract This study reports elasmobranch remains from two fossil‐rich horizons in the earliest Danian Olching Formation at Waidach, Austria. These outer neritic assemblages complement previous fine‐scale bulk‐sampling of latest Maastrichtian Waidach and document a regional faunal turnover across Cretaceous–Palaeogene (K–Pg) boundary. The show homogeneity species richness are dominated by squaliforms. fauna comprises 16 belonging to 12 genera including several new taxa ( Centrodeania rugosa...

Simultaneously investigating the effects of abiotic and biotic factors on diversity dynamics is essential to understand evolutionary history clades. The Grande Coupure corresponds a major faunal turnover at Eocene–Oligocene transition (EOT) (~34.1 33.55 Mya) defined in western Europe as an extinction insular European mammals coupled with arrival crown clades from Asia. Here, we focused species-rich group endemic artiodactyls determine drivers during environmental disruptions EOT. Using...

Abstract: Bulk sampling of phosphate‐rich horizons within the Late Cretaceous Anglo‐Paris Basin yielded numerous teeth members Squatiniformes. Along with isolated tooth remains, two museum specimens comprising partial articulated encoskeletal remains including holotype species Squatina cranei Woodward, 1888 a are described, and new subgenus Cretascyllium is proposed for genus high degree heterodonty triangular anterior teeth. The (Cretascyllium) comb. nov. hassei referred to this subgenus....

Both biotic and abiotic factors likely played a role in influencing the diversification patterns of clades. Although environmental forcing on long-term evolution biodiversity has been explored for invertebrate clades, little is known about how vertebrates groups responded to changes. Among vertebrates, fishes (ray-finned elasmobranchs) have long, rich complex evolutionary history comprising numerous extinction events. Yet, knowledge causes diversity fluctuations these most speciose aquatic...

Modern neoselachian sharks may be separated from more basal relatives by the presence of tooth enameloid comprising three layers. Although microstructure studies were mostly used in aim differentiating supposed neoselachians hybodonts, differences organization among have been recognized suggesting potential for use as a phylogenetic tool within sharks. The five taxa belonging to two orders, Hexanchiformes and Synechodontiformes, has studied. are monophyletic order with extant...