[dinosaur] Ultrasaurus in Reader's Digest

I was about eleven years old, so the year would have 1979 or so. I was
in the waiting room at an optician, to be tested for my first pair of
glasss. As I waited, I browsed a Reader's Digest and it was there that
I first read about Ultrasaurus, the greatest of all the dinosaurs!

... At least, that's how I remember it. But I know memories can be
deceptive, and after all it WAS forty years ago.

The thing is, I can't find that Reader's Digest. I have the much
earlier 1973 article in RD, by Jean George, about Supersaurus, and
it's POSSIBLE that the optician had a six-year-old Reader's Digest in
a waiting room and that's what I read, and that my mind is filling in
missing pieces. But I don't think so: I'm pretty sure it was
Ultrasaurus I was reading about.

As some of you will know, I am part way through a project to
reconstruct the history of Jensen's big three Dry Mesa sauropods: a
timeline summarising what I've found so far can be found at
https://urldefense.proofpoint.com/v2/url?u=https-3A__svpow.com_2019_07_17_supersaurus-2Dtimeline_&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=rRlOPi0W0w9TDLHsSzNvlZPLsHq8YXMJAFsGJsekG1M&s=D90RQKD9flvl5s6BMQBrR2hF0-37AZupJSebv0zbV1I&e=  and this is part of
a larger project re-evaluating Supersaurus, indexed at
https://urldefense.proofpoint.com/v2/url?u=https-3A__svpow.com_supersaurus-2Dand-2Dco-2Din-2D2019_&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=rRlOPi0W0w9TDLHsSzNvlZPLsHq8YXMJAFsGJsekG1M&s=AWcAf-EFoJRI7tZFcIP5u-cJoaEcpUshKugpzextVso&e= 

As part of that project — and also for sheer nostalgia — I would LOVE
to recover a copy of that 1979-or-thereabouts Reader's Digest article
about Ultrasaurus. (It can't have been from before 1979, as that's
when the not-really-type scapulocoracoid was found and the name
coined.) But RD's own search facilities are pretty wretched:
https://urldefense.proofpoint.com/v2/url?u=https-3A__www.rd.com_tmbi-5Ffirst-5Fassociated_magazine_&d=DwIFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=Ry_mO4IFaUmGof_Yl9MyZgecRCKHn5g4z1CYJgFW9SI&m=rRlOPi0W0w9TDLHsSzNvlZPLsHq8YXMJAFsGJsekG1M&s=7oS6aPEZKPHwf8pnnkdhShAe0RUG6Ktsy9PcL0ZKGQk&e=  and can't find
anything. Certainly a search for "ultrasaurus" or even "supersaurus"
finds nothing.

Can anyone help? I have no idea how, really, but if there's any
community that can come up with something, it's this one.

-- Mike.