Turtles of the total clade Pan-Carettochelys have a relatively poor fossil record that extends from the Early Cretaceous. The clade is only found in Asia during the Cretaceous, but spreads to Europe and North America during the Eocene. Neogene finds are restricted to Europe, Africa and Australia, whereas the only surviving species, Carettochelys insculpta, lives in New Guinea and the Northern Territories of Australia. The ecology of fossil pan-carettochelyids appears similar to that of the extant C. insculpta, although more primitive representatives were likely less adapted to brackish water. Current phylogenies only recognize three internested clades: Pan-Carettochelys, Carettochelyidae and Carettochelyinae. A taxonomic review of the group concludes that of 25 named taxa, 13 are nomina valida, 7 are nomina invalida, 3 are nomina dubia, and 2 are nomina nuda.

The Southeast Asian silurid catfish genus Wallagonia Myers, 1938, although regarded as a junior synonym of Wallago Bleeker, 1851 by recent authors following Myers (1948), differs fundamentally from it in many external and osteological characters. The genera evidently have been distinct since at least the middle Miocene and apparently are not closely related to each other. Wallagonia seems most similar to the silurid genus Ompok. Wallago differs most strikingly from all other silurids in having a much longer gape, extending ventroposteriorly well beyond the eyes. The extremely elongate upper jaw has a unique bony composition and suspension. It consists of three bones: the toothed premaxillary bone anteriorly, and the toothless suborbital and first postorbital bones posteriorly. The premaxillary bone is partially suspended from the cranium by the infraorbital bone. The closest relatives of Wallago have not been identified. Wallagonia and Wallago have no previously reported fossil records. Fossils of the family Siluridae have been identified as representatives of the Eurasian temperate genus Silurus (Kobayakawa, 1989). Here an extinct species of Wallago is described, W. maemohensis, on the basis of a complete cranium with attached, fully toothed left premaxillary in an unusually fine state of preservation from a Miocene deposit near Lampang in northern Thailand. Fossil catfishes previously reported from Thailand belong to the families Bagridae and Pangasiidae and are from Pliocene deposits (Roberts and Junmongthai 1999).

Placobdella hollensis was originally named Clepsine hollensis by Whitman (1892) from specimens collected near Woods Hole, Massachusetts; however, type specimens were neither declared nor deposited. Specimens of P. hollensis were collected from Coonamessett Pond in Barnstable County (47°37′10.25″N, 70°34′20.42″W), Massachusetts, on 4 and 30 May, 2013. Their acquisition from the general locality where Whitman (1892) collected specimens facilitated redescription of P. hollensis. A neotype is designated to stabilize the concept of P. hollensis. Placobdella hollensis is unique among its congeners in its possession of accessory “eyes.” Placobdella hollensis is modestly papillated and has a dorsomedial row and a pair of paralateral rows of unpigmented papillae, two rows of three paramedial pre-anal papillae, and two rows of two paralateral pre-anal papillae. Unlike P. ali, P. multilineata, P. papillifera, and P. parasitica, the ventrum of P. hollensis does not have stripes. Placobdella hollensis does have two thin paramedial dark lines on its ventrum, which are also present in P. papillifera. Molecular comparison of CO-I sequence data from P. hollensis revealed differences of 14% from P. multilineata, 15% from P. picta, 15% to 16% from P. papillifera, 16% from P. translucens, 16% to 17% from P. rugosa, 16% to 17% from P. ornata, 17% from P. montifera, 17% to 18% from P. ali, and 18% from P. biannulata.

Instances of vertebrates supplementing their diets through the ingestion of gastroliths have been observed or documented in numerous organisms, including birds, crocodiles and dinosaurs. Although not uncommon, this behavior can be motivated by a wide range of factors that include endoparasite removal, stomach cleaning, or calcium supplementation during eggshell formation. As plant-based diets are often mineral deficient, the use of gastroliths as calcium supplements may play an important role in the reproductive biology of egg-laying herbivorous reptiles. Whereas gravid females of some species of herbivorous reptiles have been shown to seek out calcareous gastroliths, the occurrence or prevalence of gastroliths in gravid females remains unknown for many species. Using field observations and radiographs, we studied patterns of gastrolith ingestion by adult female gopher tortoises (Gopherus polyphemus), a herbivorous species of testudinoid turtles. Gastroliths documented included fossil seashells, calcareous stones and carnivore feces containing vertebrate bones. The prevalence of gastroliths was significantly different between gravid and non-gravid tortoises. We suggest this behavior is a means of supplementing calcium intake during eggshell formation and may play a part in the female reproductive biology of this species.