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CLOCKWISE FROM TOP LEFT: COURTESY OF THE ROYAL TYRRELL MUSEUM OF PALAEONTOLOGY, DRUMHELLER, CANADA; SCIENCE PICTURE CO/SCIENCESOURCE; DAVIDE BONANDONNA/NATIONAL GEOGRAPHIC CREATIVESperm Counts
Plummet
❯
SPERM COUNTS have
plunged 52.9 percent in
the past 39 years in North
America, Europe, Australia and New
Zealand, according to a July analysis
in Human Reproduction Update. This
trend is worrisome because, besides
affecting male fertility, men with
lower sperm counts also have higher
rates of heart disease and cancer.
They also die at younger ages.
The analysis involved 185 studies
of 42,935 men conducted between
1973 and 2011. (Men in other parts
of the world weren’t included
because solid data isn’t available.)
Environmental factors are the
likely culprits. For example, men
with low sperm counts might have
been exposed in utero to cigarette
smoke or chemicals that disrupt
crucial hormone levels.
“This is the canary in the coal
mine,” says Shanna H. Swan, a
study co-author at Icahn School of
Medicine at Mount Sinai in New
York, “because it has large economic
implications about men’s fertility and
health.” — LINDA MARSAHow to
Preserve
a Dinosaur
❯
ROYAL TYRRELL MUSEUM technician Mark Mitchell estimates
he spent 7,000 hours chipping away at rock to uncover this
112 million-year-old dinosaur fossil, put on display at the
Alberta museum in May. Described formally in August in Current
Biology, the animal’s name, Borealopelta markmitchelli, is a nod
to Mitchell’s dedication.
The plant-eating, tanklike nodosaur is unusually well preserved,
including its hefty body armor, large shoulder spikes and even pieces
of soft tissue. Only
the animal’s front
half was found;
its partly exposed
innards include the
fossilized remnants
of a last leafy meal.
Don Henderson,
the Royal Tyrrell’s
curator of dinosaurs,
believes that soon
after death, the
nodosaur’s bloated
carcass floated down
a river out to the
ancient Albertan sea
where “eventually the
body went pop, and
he sank like a stone.”
Sediment must have
then rapidly buried
the body, preserving
it with lifelike detail.
— SYLVIA MORROWExtremely rare among armored dinosaur fossils, the
remains of Borealopelta markmitchelli were preserved
with many of its spikes and bony plates in place
(above), providing a detailed guide to illustrating
what it looked like 112 million years ago (below).