The Briar Creek Bonebed (Artinskian, Nocona Formation) in Archer County is one of the richest sources of Dimetrodon bones in the Lower Permian of Texas, USA. Based on size, a small (D. natalis), an intermediate (D. booneorum), and a large species (D. limbatus) have been described from this locality. It has been proposed that these traditionally recognised species represent an ontogenetic series of only one species. However, the ontogenetic series hypothesis is inconsistent with the late ontogenetic state of the small bones, as suggested by their osteology and degree of ossification. Histological analysis of newly excavated material from the Briar Creek Bonebed has resolved some of the discretion between these two competing hypothesis, confirming the coexistence of a small (D. natalis) with at least one larger Dimetrodon species. An external fundamental system is present in the largest sampled long bones identified as D. natalis. The histology of D. natalis postcrania is described as incipient fibro lamellar bone. This tissue is a combination of parallel-fibred and woven-fibred bone that is highly vascularised by incipient primary osteons. The species status of D. booneorum and D. limbatus remain unresolved.

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The Lower Muschelkalk Vossenveld Formation has yielded a diverse and abundant vertebrate fauna. In this contribution, we describe a small saurichthyid fish, Saurichthys dianneae sp. nov., from the Winterswijk locality in the eastern Netherlands. This species is represented by multiple specimens ranging from the Bithynian to the early Illyrian (middle-early late Anisian) in age. The material from Winterswijk includes articulated postcranial material, which is unusual for a saurichthyid from the Muschelkalk. Saurichthys dianneae sp. nov. is diagnosed by its small size (less than 10 cm in total length), elongate shape, extremely constricted interorbital region, neural arches lacking well-developed neural spines, and morphology and organization of the squamation. The slender body shape, flattened upper jaw, and dorsally directed orbits suggest that S. dianneae may have lived near the sea surface. Saurichthys with a similar body shape are known from the Middle Triassic of Germany, and indicate that these small, surface-dwelling saurichthyid fishes may have been widespread in coastal areas of the Middle Triassic Muschelkalk Sea.

During recent years, regular round structures have been collected from the top of Bed 12 of the Vossenveld Formation (Lower Muschelkalk, lower Middle Triassic, Anisian) in the Winterswijk area, eastern Netherlands. These are here illustrated and described as probable remains of jellyfish.

The Palaeozoic-Mesozoic transition is characterized not only by the most massive Phanerozoic mass extinction at the end of the Permian period, but also its extensive aftermath and a prolonged period of major biotal recovery during the succeeding Middle to Late Triassic. Particularly, Anisian insect species from units of the Lower to Middle Muschelkalk from the Central European Basin are rare. The specimens described here originated from the Anisian Wellenkalk facies (Lower Muschelkalk), Vossenveld Formation of the Winterswijk quarry, The Netherlands, and from the orbicularis Member (lowermost Middle Muschelkalk, Anisian) of Esperstedt near Querfurt (Saxony-Anhalt). Thus, the described insect remains from Winterwijk and Esperstedt expand our knowledge about Middle Triassic terrestrial arthropod communities and their palaeodiversity. A new species of Chauliodites (C. esperstedti sp. nov) is introduced.