On the average, how long would a human being remain recognizable after being buried under normal ecological circumstances?
Until the dental records decay. Depending on what it was buried in(i.e. frozen dirt, sand, clay, etc.) it could be identifiable long after civilization, as we know it, exists. Maybe up to 30,000 years if the conditions were ideal.
Bodies decay at different rates in different substrates. You can imagine how frozen dirt would hinder biological decomposition as opposed to being buried in your average serial killer’s backyard, with sprinklers, earthworms, and other organisms to accelerate the process.
Without the dental records a body could only be defined as male or female, an approximated age, length of burial, and of course wounds that may have left marks on the bones. Other identifiers are if you had circumstantial evidence tying the body to that location.
And here I thought this thread was going to be about how to achieve undying fame, or the rules for eligibility for being on a stamp, or how they can get away with renaming Route 9 the Representative Billy Bob Joe Smith Highway, when Billy Bob Joe is still alive and kicking.
At any rate, the Perfect Master of All Knowledge has at least touched upon the subject:
I remember reading in some novel–maybe All Quiet on the Western Front–that the facial features of a recently-dead body will quickly lose their distinctiveness and somehow assume a generic “death mask” that has little resemblence to the person when alive. Is this true?
I had to identify my father, three days after his death (fortunately, it was December in Britain). He was immediately recognizable. So - based on a statistical sample of one - no, facial features do not conform to a generic death mask.
(Identifications are made fairly routinely, under worse circumstances than that.)