Qiang Li and colleagues have created “cyborg” pancreatic organoids that combine stretchy miniature electronics with stem cell-derived pancreatic islets, using the implanted electronics to monitor electrical activity related to glucose regulation in maturing α and β cells. Islet α and β cells secrete glucagon and insulin hormones, in response to electrical changes in the cell membrane. The researchers also used the electronics to stimulate the cells to enhance their glucose responsiveness and show how that responsiveness changes as the cells mature, how it is affected by different chemical compounds and circadian hormones, and how it is related to gene expression. Together, the cyborg organoids offer a path to study the biology and trace the maturation of α and β cells at the single-cell level, with an eye toward potentially treating or engineering new pancreatic islets in people with diabetes. In a related Perspective, Jochen Lang and Matthieu Raoux discuss how the cyborgs could be used to guide the growth of mature human pancreatic organoids for regenerative medicine and other applications.

A new Spinosaurus species uncovered in northern Niger by Paul Sereno and colleagues appears to have been a wading predator of fish like its close relatives, but it lived as many as 1,000 kilometers inland from the Tethys Sea. The fossil find may represent a third phase of evolution for this group of massive, fish-eating dinosaurs, according to Sereno et al. The new species Spinosaurus mirabilis, uncovered in the central Sahara near Sirig Taghat (“no water, no goat” in Tamasheq, the local Berber language), lived with long-necked dinosaurs in a riparian habitat 100-95 million years ago. Sereno et al. suggest there were three phases of spinosaur evolution: a first phase that began in the Jurassic Period when the reptiles developed their elongated skull for fish-catching; a second Early Cretaceous Period phase that saw the spread of spinosaurs as predators all along the coast of the Tethys Sea; and a third phase where spinosaurs like S. mirabilis specialized as shallow water predators in northern Africa and South America. S. mirabilis was similar in size and skeletal form to Spinosaurus aegyptiacus, but was crowned with a unique scimitar-shaped bony crest that may have been used for visual display rather than locomotion or hunting.