BBC News
 A
90-million-year-old tick, fossilised in amber, and which could
have fed on the blood of dinosaurs, has stirred up suggestions
that it might contain the DNA of the fearsome creatures.
But the scientists
in charge of the parasite say they do not intend to turn the film
Jurassic Park into reality, as they maintain the chances of finding
any readable DNA are slim.
Instead, they
want to preserve the specimen as it shows unique features not
seen in modern day ticks.
The tick is
the oldest known fossil of the order Parasitiformes. Its discovery
increases the order's age by 50 million years, says Hans Klompen,
professor of entomology at Ohio State University, where the parasite
is being studied.
Dinosaur blood
Carios jerseyi,
as it is technically known, is an Argasid, or soft tick. The fossil
is estimated to be between 90 and 94 million years old.
If C. jerseyi
really is that old, it could have fed off the blood of dinosaurs.
"Ticks will feed on anything that has blood," Klompen
says.
"Would
ticks feed on dinosaurs if dinosaurs were still around today?
You bet," he adds. "Nearly all soft ticks will feed
on a wide range of hosts. If it has blood, a soft tick will go
for it."
But the ancient
tick's precise feeding habits will remain a mystery, since scientists
want to preserve the unique specimen and not break it up.
Fed on birds
Although Carios
jerseyi lived during the height of the dinosaur era, the upper
Cretaceous period, Klompen is pessimistic that any DNA from dinosaurs
could be extracted.
"You
won't reconstruct a dinosaur from the blood of a blood-feeding
arthropod," he said. The tick was discovered several years
ago in a large rock excavated from an amber outcrop in central
New Jersey, US. It measures 0.520 mm by 0.445 mm (0.02 by 0.01
inches).
Scientists
are puzzled by its three dozen or so tiny bristle-like hairs aligned
in two rows on its back.
"It was
very surprising," Klompen says: "Soft ticks normally
have far fewer hairs over their entire body. But this tick is
much closer to what I anticipate as the evolutionary starting
point of all ticks."
"Most
of the hairs on the body of a mite or a tick are probably contact
receptors," he adds.
Feather clue
"If something
gets too close, the tick notices it's there. Other Argasidae have
hairs, but they're typically much longer and arranged chaotically."
Rather than
feasting on dinosaurs, Klompen says, it is more likely that C.
jerseyi fed on sea-faring birds.
The specimen
shows similarities to a group of ticks known for feasting on birds.
And a small feather (7.5 mm, or 0.3 inches) from an unidentified
bird was also found preserved in the same outcrop of amber.
"Finding
this feather suggests that the tick might have travelled to North
America on a seabird," Klompen said.
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