Pridoli first appearances

Chondrichthyes (; ) is a class of jawed fish that contains the cartilaginous fish or chondrichthyans, which all have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or bony fish, which have skeletons primarily composed of bone tissue. Chondrichthyes are aquatic vertebrates with paired fins, paired nares, placoid scales, conus arteriosus in the heart, and a lack of opercula and swim bladders. Within the infraphylum Gnathostomata, cartilaginous fishes are distinct from all other jawed vertebrates.

Osteichthyes ( ; ), also known as osteichthyans or commonly referred to as the bony fish, is a diverse clade of vertebrate animals that have endoskeletons primarily composed of bone tissue, encompassing both the conventional bony fishes and, in a cladistic sense, all tetrapods. They can be contrasted with the Chondrichthyes (cartilaginous fish) and the extinct placoderms and acanthodians, which have endoskeletons primarily composed of cartilage. The vast majority of extant fish are members of Osteichthyes, being an extremely diverse and abundant group consisting of 45 orders, over 435 families

Sarcopterygii (; )—sometimes considered synonymous with Crossopterygii ()—is a clade (traditionally a class or subclass) of vertebrate animals which includes a group of bony fishes commonly referred to as lobe-finned fishes. These vertebrates are characterised by prominent muscular limb buds (lobes) within their fins, which are supported by articulated appendicular skeletons. This is in contrast to the other clade of bony fishes, the Actinopterygii, which have only skin-covered bony spines supporting the fins.

Prototaxites is an extinct genus of large macroscopic eukaryote dating from the Late Silurian until the Late Devonian periods. Prototaxites formed large trunk-like structures up to wide, reaching in height, made up of tiny interwoven tubules around in diameter, making it by far the largest land-dwelling organism of its time.

Arthropleuridea, from Ancient Greek ἄρθρον (árthron), meaning "joint", and πλευρά (pleurá), meaning "rib", is an extinct subclass of myriapod arthropods that flourished during the Carboniferous period, having first arisen during the Silurian, and perishing in the Early Permian. Members are characterized by possessing diplosegement (fused "double segments", as in modern-day millipedes) paranotal tergal lobes separated from the body axis by a suture, and by sclerotized plates buttressing the leg insertions. Despite their unique features, recent phylogenetic research suggests Arthropleuridea be i

Eoarthropleura was a genus of millipede-like creatures which lived between the Late Silurian and Late Devonian periods. It reached in length. Fossils, mainly of cuticle fragments, have been found in Europe (Rhineland-Palatinate, Germany and Shropshire, England) and North America (New York, USA and New Brunswick, Canada). It is the earliest known member of the Arthropleuridea, and the oldest known terrestrial animal of North America.

Tortilicaulis is a moss-like plant known from fossils recovered from southern Britain, spanning the Silurian-Devonian boundary (around ). Originally recovered from the Downtonian of the Welsh borderlands, Tortilicaulis has since been recovered in the famous Ludlow Lane locality.