👉 The term "Hyalospheniidae" refers to a group of extinct marine reptile species that lived during the Mesozoic era, approximately 75-68 million years ago. These creatures were known for their distinctive appearance and ability to breathe underwater using their gills. They are characterized by having large eyes with a characteristic "hairy" eye patch on the front part of the head. The term is named after the Greek words "Hydro" (water) and
