Above is an image of an Hildoceras bifrons (Bruguière, 1789) ammonite fossil. It dates to the Jurassic Period (Toarcien) and was found at La Verpilliere (Isère), France. It was displayed at Muséum National D'Historie Naturelle Jardin Des Plantes Paléontologie et Anatomie Comparée, Paris, France. Image taken August 2009.
The species was named by French zoologist Jean Guillaume Bruguière (1749-1798). While the name ammonite was derived from Egyptian deity Ammon who was represented by a symbol looking like a coiled ram horn. In medieval England, the fossil was seen by some as a petrified coiled snake. The genus of this ammonite is associated with St. Hilda of Whitby, Yorkshire, England. Legend has it she turned a plague of snakes to stone. As such an American palaeontologist Alpheus Hyatt (1838-1902) named an ammonite genus Hildoceras (Hyatt, 1876) after her.