I didn't see anyone talking about this on /r/UFOs or any related subs so I wanted to post this here for discussion. I also haven't seen anyone directly ask Elizondo about these claims in his book in any interview. Below is a slight paraphrase from Imminent by Luis Elizondo in Chapter 11: Biological Remains. The bold emphasis is my own.
Several of the senior officials I worked with told me that when one of my colleagues worked at the CIA some decades earlier, he was given an official autopsy report of the dissection of a non-human body that was recovered from an unspecified crashed UAP. The report stated that the brain had no convolutions, the wrinkle exterior portion of the brain. Rather, what was described was a smooth surface similar to lower functioning animals here on earth. It also described a conjoined gut and liver, and a three chambered heart like reptiles. The author of the autopsy came to the conclusion that the cadaver did not appear to have the requisite brain capacity to design and create aircraft capable of such stunning maneuverability. It was postulated that it might be some sort of biological automaton created by something else with a greater intellect. In that era at the CIA, brain science considered smooth exterior brain surfaces to be indicative of an extremely low animal intelligence, which was incapable of tool making. A smooth brain was suspected to have no sophisticated communication capability beyond sight, smell or pheromones, with primitive vocal noises. Let me emphasize that this is what was told to me at the time.
He goes on to speculate that these were complicated "biological machines."
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