ANCIENT AMERICAN LAKE— BRADLEY 283 



grasshopper were common, but if there were butterflies and moths 

 they have left no trace. Animals coming to the lake shore must 

 have found it a disagreeable experience, for there they met clouds of 

 mosquitoes, black fhes and gnats, and larger flies that bit savagely. 

 Spiders and the lowly cockroach have been found, and even one mite, 

 which, incidentally, has the distinction of being the most ancient mite 

 in North America — America's oldest louse, if you will. 



Crocodiles shared with various river turtles the sluggish parts of the 

 streams near the lake. Land tortoises, rivaling in size the famous ones 

 from the Galapagos Islands, plodded through the sandy lowlands. 

 Snakes, too, there were; indeed, the most nearly perfect fossil snake 

 ever found in the Western Hemisphere came from these lake beds. 

 Water birds, like the loons, sandpipers, and rails, must have been nu- 

 merous, for impressions of feathers are common on the slabs of rock 

 that were once mud flats bordering the lake. Of the birds themselves 

 we know next to nothing — fossil birds are rarae aves indeed. Oddly 

 enough, however, the one remarkably fine fossil bird that has been 

 found in these lake beds was a native of the uplands similar to our 

 ruffed grouse. 



Despite the modern aspect of the forest that encircled ancient Lake 

 Uinta, the warm-blooded mammals that Uved in it were decidedly 

 strange. Particularly strildng was the ancestor of the modern horse, 

 for it stood no higher at the withers than an Airedale pup. Its back 

 arched somewhat, and instead of one hoof to the foot it had four slender 

 hoofs on each front foot and three on each hind foot. These hoofs, 

 however, bore less of the animal's weight than did a pad at the base 

 of the toes. The teeth of this primitive horse, unlike those of its 

 modern descendant, were adapted to feeding upon leaves and soft, 

 lush plants, for the West at that time was green with forest and 

 meadow. Only through the following millions of years did it become 

 the semiarid region that we know today. 



A fisherman peering down through the clear water to see what man- 

 ner of fish there were among the pond weeds would not have been dis- 

 appointed. Perch and other fresh-water fish inhabited the weedy 

 bays, but they were greatly outnumbered by varieties of herring. To- 

 day, most herring Uve in the sea, though a few go up rivers to spawn 

 and a few others five in rivers. Thirty million years ago more varie- 

 ties apparently went into fresh water to spawn, for those found as 

 fossils are of two sizes — fry that had not long left the spawning ground 

 and adults that had presumably returned from the sea to spawn. 

 Least to be expected so far from their usual marine environment were 

 the large sting rays. The occurrence of so many forms that spent 

 part of their fives in marine water impfies that for a long time a per- 

 ennial river ran from Lake Uinta to the sea, even though the lake was 

 probably 600 or 800 miles inland. So great a distance from the sea 



