Artist’s reconstruction of the ancestral snake. From Hsiang et al. The origin of snakes: revealing the ecology, behavior, and evolutionary history of early snakes using genomics, phenomics, and the fossil record.

Fossil stem of the Jurassic royal fern Osmunda pulchella, as first described in Bornfleur et al. Osmunda pulchella sp. nov. from the Jurassic of Sweden—reconciling molecular and fossil evidence in the phylogeny of modern royal ferns (Osmundaceae).

Comparative limb morphogenesis in the lizard Aspidoscelis uniparens and chameleon Chamaeleo calyptratus, with distinctive ‘split-foot’. From Diaz Jr & Trainor, Hand/foot splitting and the ‘re-evolution’ of mesopodial skeletal elements during the evolution and radiation of chameleons.

Geographic variation in the salamander Aneides lugubris. From Reilly et al. An integrative approach to phylogeography: investigating the effects of ancient seaways, climate, and historical geology on multi-locus phylogeographic boundaries of the Arboreal Salamander (Aneides lugubris).

Hypothetical scenario of evolutionary formation of the phoronid body plan. From Temereva & Malakhov, Metamorphic remodeling of morphology and the body cavity in Phoronopsis harmeri (Lophotrochozoa, Phoronida): the evolution of the phoronid body plan and life cycle.

Flowers of the native Chinese lily genus Nomocharis. From Gao et al. Morphological and ecological divergence of Lilium and Nomocharis within the Hengduan Mountains and Qinghai-Tibetan Plateau may result from habitat specialization and hybridization.

Behavior on water of ‘sailing spiders’.  From Hayashi et al. Sail or sink: novel behavioural adaptations on water in aerially dispersing species.

Histological growth series of dwarf deer femora with skeletal reconstructions. From Kolb et al. Growth in fossil and extant deer and implications for body size and life history evolution.

Lateral view of various species of the crustacean class Malacostraca. From Kutschera et al. Calcitic sclerites at base of malacostracan pleopods (Crustacea) – part of a coxa.

Various forms of Pendergrast’s organ located on the abdomen of females of 11 species of the ‘shield bug’ Acanthosomatidae. From Tsai et al. Maternal care in Acanthosomatinae (Insecta: Heteroptera: Acanthosomatidae)—correlated evolution with morphological change.

General serotonin-like immunoreactivity pattern in the ganglia of sea spider walking legs. From Brenneis & Scholtz, Serotonin-immunoreactivity in the ventral nerve cord of Pycnogonida – support for individually identifiable neurons as ancestral feature of the arthropod nervous system.

Phylogenetic relationships of the different genera within the subtribe Mycalesina. From Aduse-Poku et al. Systematics and historical biogeography of the old world butterfly subtribe Mycalesina.