Question: What happened in 1976 that impacted this primate's classification as Endanger?
Sentence: Not only had they found documentation that 151 of these primates had inadvertently made their way from the Harvard-affiliated New England Regional Primate Research Center into the exotic pet trade through the aforementioned loophole, but in October 1976, over 800 cotton-top tamarins were imported into the United States in order to beat the official listing of the species under the ESA.
Answer in sentence: yes