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ABSTRACT Hatching synchronisation is widespread in oviparous taxa. It has been demonstrated that many species use sounds to coordinate synchronous hatching, being widespread among archosaurs (birds and crocodilians). Recent studies have shown that some turtle species produce vocalisations from within the egg, but the role of this behaviour in synchronising hatch is untested. The small amount of information about sound production by turtle embryos, limited to a handful of closely related species, precludes any inferences based on differences in their ecology, reproductive behaviour and phylogenetic context. With the goal to investigate if coordinated synchronous behaviour is mediated by within‐egg vocalisations in turtles, we recorded clutches from six different turtle species. The selected animals present different ecological and reproductive niches and belong to distinct phylogenetic lineages at the family level. We aimed to understand: (1) what is the phylogenetic distribution of within‐egg vocal behaviour among turtles; (2) if asynchronous turtle species vocalise from within the egg; (3) if clutch size influences synchronous behaviour and (4) if within‐egg turtle calls follow any phylogenetic signal. The new evidence provides light to the current knowledge about synchronous behaviour and within‐egg calls, challenging previous hypothesis that within‐egg sounds are accidentally produced as side‐effects of other behaviours.

Some reptile species can consume their own shed skin or that of conspecifics; despite its prevalence, the benefits of eating shed skin remain poorly understood. Here, we report a field observation in which a Vallarta Mud Turtle (Kinosternon vogti) consumed a snake shed skin of Masticophis lineatus (Bocourt, 1890) in Bahía de Banderas, Nayarit, Mexico. This type of record could allow us to understand the keratophagous behaviour between and within reptile species.

Here, the authors record acoustic communication in 53 species commonly considered non-vocal and reconstruct acoustic communication as originating 407 million years ago.

We describe a new subspecies of Amyda ornata (Gray, 1861) from the southeastern parts of Bangladesh (Chittagong hill tracts), adjacent regions of north-eastern India (Mizoram, Assam and Tripura) and Myanmar, based on morphological characteristics. The holotype comprises some skeletal elements held by the Natural History Museum of Vienna; the five paratypes consist of living specimens in the private collection of PP “Turtle Island” (a turtle conservation zoo in Graz, Austria). After the genetic identity had been determined in a previous investigation, the morphological description was carried out by examining living specimens and photo documents; and additionally, by evaluating the computed tomography of further living animals with exact location data. Amyda ornata jongli ssp. nov. differs from the other Amyda ornata subspecies mainly by its relatively compact and stout head in subadults and adults, its paler, greyish and less contrasting colouration missing distinct bright yellow pigments, ochre-coloured irises, and the existence of more distinct tubercles in the neck region and in the posterior section of the carapace than both other subspecies of Amyda ornata. The tubercles along the front of the carapace protrude clearly in subadult and adult specimens. This softshell turtle is heavily exploited within its limited distribution. Therefore, special comments on conservation aspects are given together with a final discussion on distribution and systematics.

Abstract Despite the relevance of chemical communication in vertebrates, comparative examinations of macroevolutionary trends in chemical signaling systems are scarce. Many turtle and tortoise species are reliant on chemical signals to communicate in aquatic and terrestrial macrohabitats, and many of these species possess specialized integumentary organs, termed mental glands (MGs), involved in the production of chemosignals. We inferred the evolutionary history of MGs and tested the impact of macrohabitat on their evolution. Inference of ancestral states along a time-calibrated phylogeny revealed a single origin in the ancestor of the subclade Testudinoidea. Thus, MGs represent homologous structures in all descending lineages. We also inferred multiple independent losses of MGs in both terrestrial and aquatic clades. Although MGs first appeared in an aquatic turtle (the testudinoid ancestor), macrohabitat seems to have had little effect on MG presence or absence in descendants. Instead, we find clade-specific evolutionary trends, with some clades showing increased gland size and morphological complexity, whereas others exhibiting reduction or MG loss. In sister clades inhabiting similar ecological niches, contrasting patterns (loss vs. maintenance) may occur. We conclude that the multiple losses of MGs in turtle clades have not been influenced by macrohabitat and that other factors have affected MG evolution.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

For a long time, turtles of the family Geoemydidae have been considered exceptional because representatives of this family were thought to possess a wide variety of sex determination systems. In the present study, we cytogenetically studied Geoemyda spengleri and G. japonica and re-examined the putative presence of sex chromosomes in Pangshura smithii. Karyotypes were examined by assessing the occurrence of constitutive heterochromatin, by comparative genome hybridization and in situ hybridization with repetitive motifs, which are often accumulated on differentiated sex chromosomes in reptiles. We found similar karyotypes, similar distributions of constitutive heterochromatin and a similar topology of tested repetitive motifs for all three species. We did not detect differentiated sex chromosomes in any of the species. For P. smithii, a ZZ/ZW sex determination system, with differentiated sex chromosomes, was described more than 40 years ago, but this finding has never been re-examined and was cited in all reviews of sex determination in reptiles. Here, we show that the identification of sex chromosomes in the original report was based on the erroneous pairing of chromosomes in the karyogram, causing over decades an error cascade regarding the inferences derived from the putative existence of female heterogamety in geoemydid turtles.