A Small Glass Container by Tom Hebert
Approx. 98,000 words.
Published on October 18, 2013.
A few million humans are isolated on a earth-like planet. They occupy a continent that has an ecosystem that is identical to North America of 100,000 BC, complete with Wooly Mammoths and Saber Toothed Tigers. They have just discovered that alien races also inhabit the planet and that these aliens are hostile. This is the first of three books in the New American Continent series.