It is impossible to say which of these three observers actually made the first discovery of Jurassic dinosaurs; whatever doubt there is is in favor of Mr. Reed.
Professor Lakes, accompanied by his friend Mr. E.L. Beckwith, an engineer, was, one day in March, 1877, hunting along the "hogback" in the vicinity of Morrison, Colorado, for fossil leaves in the Dakota Cretaceous sandstone which caps the ridge, when he saw a large block of sandstone with an enormous vertebra partly imbedded in it. He discussed the nature of the fossil with his friend (so he told me) and finally concluded that it was a fossil bone. He had recently come from England and had heard of Professor Phillips' discoveries of similar dinosaurs there. He knew of Professor Marsh of Yale from his recent discoveries of toothed birds in the chalk of Kansas, and reported the find to him. As a result, the specimen, rock and all, was shipped to him by express at ten cents a pound! And Professor Marsh immediately announced the discovery of _Titanosaurus_ (_Atlantosaurus_) _immanis_, a huge dinosaur having a probable length of one hundred and fifteen feet and unknown height. And Professor Lakes was immediately set at work in the "Morrison quarry" near by, whence comes the accepted name of these dinosaur beds in the Rocky Mountains. Professor Lakes once showed me the exact spot where he found his first specimen.
Mr. Lucas, teaching his first term of a country school that spring in Garden Park near Cañon City, as an amateur botanist was interested in the plants of the vicinity. Rambling through the adjacent hills in search of them, in March, 1877, he stumbled upon some fragments of fossil bones in a little ravine not far from the famous quarry later worked for Professor Marsh. He recognized them as fossils and they greatly excited, not only his curiosity, but the curiosity of the neighbors. He had heard of the late Professor Cope and sent some of the bones to him, who promptly labelled them _Camarasaurus supremus_.
The announcement of these discoveries promptly brought Mr. David Baldwin, Professor Marsh's collector in New Mexico, to the scene. Only a few months previously he had discovered fossil bones in the red beds of New Mexico, the since famous Permian deposits. He naturally explored the same beds at Cañon City, immediately below the dinosaur deposits, and soon found the still very problematical _Hallopus_ skeleton, at their very top, a specimen which after nearly forty years remains unique of its kind.