The trackway of a huge sauropod, and the longest sauropod trackway currently known, reaching 155 m in length, has been excavated in Eastern France, alongside a shorter theropod trackway. They have been precisely dated to the early Tithonian (Late Jurassic), when the trackway site was located at the southeastern margin of the carbonate-dominated Jura platform, in a protected littoral mudflat environment. The footprints are preserved to various degrees along the trackways, depending on the initial condition of the sediment of various competences. The best-preserved section of the sauropod trackway allows this specimen to be attributed to Brontopodus plagnensis nov. isp. This new trackway site, alongside other Early Jurassic Swiss and French tracksites yielding thousands of sauropod and theropod tracks, can be considered as being the largest dinosaur megatracksite in Europe.