The superfamily Pronocephaloidea Looss, 1899 comprises digeneans occurring in the gut and respiratory organs of fishes, turtles, marine iguanas, birds and mammals. Although many life cycles are known for species of the Notocotylidae Lühe, 1909 maturing in birds and mammals, relatively few are known for the remaining pronocephaloid lineages. We report the cercariae of five pronocephaloid species from marine gastropods of the Queensland coast, Australia. From Lizard Island, northern Great Barrier Reef, we report three cercariae, two from Rhinoclavis vertagus (Cerithiidae) and one from Nassarius coronatus (Nassariidae). From Moreton Bay, southern Queensland, an additional two cercariae are reported from two genotypes of the gastropod worm shell Thylacodes sp. (Vermetidae). Phylogenetic analysis using 28S rRNA gene sequences shows all five species are nested within the Pronocephaloidea, but not matching or particularly close to any previously sequenced taxon. In combination, phylogenetic and ecological evidence suggests that most of these species will prove to be pronocephalids parasitic in marine turtles. The Vermetidae is a new host family for the Pronocephaloidea.

We describe Hedruris dratini n. sp. (Nematoda, Hedruridae) from Hydromedusa tectifera and Phrynops hilarii in Argentina based on morphological and molecular characters. Also, we provide information about its life cycle. The new species differs from other species of the genus by possessing the excretory pore, nerve ring and deirids at equal distance from the anterior end. Additionally, H. dratini n. sp. has mammilated eggs and males possess nine pairs of caudal papillae. The subadults and adults of H. dratini n. sp and H. orestiae were characterized by sequencing the small subunit ribosomal DNA (18S). We present for the first time a life cycle of a species of Hedruris that includes an amphipod as intermediate host and a reptile as definitive host. Furthermore, we analysed the host and geographic distribution of all Hedruris species. Although the genus has a cosmopolitan distribution and parasitizes a great host diversity, the majority of species have a Gondwanian distribution, with amphibians being the preferred hosts.

Turtle remains ascribed to the family Cheloniidae (Testudines, Cryptodira, Chelonioidea), collected from the lamarcki zone (Middle Turonian) at Wüllen (NW Germany) are described. The material consists of a right humerus, a scapula, a complete costalia, and costalia fragments of a single individual with the humerus indicating a primitive cheloniid of the ‘toxochelyid grade’. The present material, as well as previously recorded chelonioid humeri from the Cenomanian and Turonian of Germany illustrate a progressive diversification of chelonioids during the early Late Cretaceous.

The continental deposits of the Upper Cretaceous (Santonian) Csehbánya Formation of the Bakony Mountains in Hungary yielded abundant remains of a bothremydid side-necked turtle, which are attributed to a new species of the genus Foxemys, Foxemys trabanti. F. trabanti shows strong affinities with the European monophyletic group Foxemydina owing to the absence of pits in the upper and lower triturating surfaces, the exclusion of the jugal from the triturating surface, the separation of the Eustachian tube and the stapes by a narrow fissure, the presence of deep and narrow fossa pterygoidei, the partially closed foramen jugulare posterius and the pentagonal shape of the basisphenoid in ventral view. Among the Foxemydina the bothremydid from Iharkút is more closely related to F. mechinorum than to Polysternon provinciale from the Early Campanian of France, mainly because of the position of the occipital condyle relative to the mandibular condyles of the quadrate. The new remains represent the only record of the Foxemydina outside of Western Europe and provide the earliest known occurrence of this endemic, freshwater group in the former Mediterranean Basin. The historical biogeography of the tribe Bothremydini is investigated and a hypothesis of migration from Africa to North America via the high-latitude Thulean route is put forward.

Patterns of formation and sequence of ossification of the entire skeleton are described for the snapping turtle Chelydra serpentina, based on new and previously published data. Differences in the sequences of ossification events are described and demonstrate considerable intraspecific variation in these developmental data. The chondrocranium of a late developmental-stage specimen is described and illustrated as baseline data for comparative studies. Patterns of formation and chondrification of forelimb and hind limb elements are generally consistent with those of previous studies; however, conspicuous differences in the patterns of ossification are observed among metapodial and phalangeal elements. In the cranium, patterns of ossification of dermal elements are generally more variable than are those of endochondral elements of the braincase, and as in previous studies, endochondral elements ossify after dermal elements. Documented intraspecific variation in sequence and timing of formation, chondrification, and ossification of skeletal elements should serve as a caveat for those conducting studies of phylogeny, heterochrony, and evolution with these data. Causes of natural and induced variation are discussed briefly.

The lives of sea turtles consist of a continuous series of migrations. As hatchlings, the turtles swim from their natal beaches into the open sea, often taking refuge in circular current systems (gyres) that serve as moving, open-ocean nursery grounds. The juveniles of many populations subsequently take up residence in coastal feeding areas that are located hundreds or thousands of kilometres from the beaches on which the turtles hatched; some juveniles also migrate between summer and winter habitats. As adults, turtles periodically leave their feeding grounds and migrate to breeding and nesting regions, after which many return to their own specific feeding sites. The itinerant lifestyle characteristic of most sea turtle species is thus inextricably linked to an ability to orient and navigate accurately across large expanses of seemingly featureless ocean.

In some sea turtle populations, migratory performance reaches extremes. The total distances certain green turtles (Chelonia mydas) and loggerheads (Caretta caretta) traverse over the span of their lifetimes exceed tens of thousands of kilometres, several times the diameter of the turtle's home ocean basin. Adult migrations between feeding and nesting habitats can require continuous swimming for periods of several weeks. In addition, the paths of migrating turtles often lead almost straight across the open ocean and directly to the destination, leaving little doubt that turtles can navigate to distant target sites with remarkable efficiency.