A poetic and mysterious sentence, one of my favorites from the geology books I’ve come across through the years:
“Spinosity in animals is often the prophecy of tribal death.”
Um… could you repeat that??
To be fair, the two preceding sentences do help add some context: “In the Silurian, though they were still common, the trilobites were nevertheless on the decline… and this ebbing of their vital force is seemingly shown in many picturesque forms replete with protuberances, spines, and exaggeration of parts. As a rule, in evolution one finds that when an organic stock is losing its vital force there arises in it an exaggeration of parts, as if heroic efforts were being made to maintain the race.”
Quoted from: A Text-Book of Geology…, Part 2, Historical Geology, by Charles Shuchert. New York, London: John Wiley & Sons, Inc., 1915. p. 605.