Since its discovery in Patagonia in 1891, Necrolestes has been an enigma....The humerus of Necrolestes is wider than any other fossorial mammal's ... but this trait didn't make classification any easier. The simple triangular teeth of Necrolestes s ... have proved of little help in classifying Necrolestes ... . Enter Necrolestes.

The mystery solved In 2011, a newly discovered extinct mammal named Necrolestes was the key that unlocked the mystery of the burrowing enigma. Discovered by co-author Rougier in South America, Necrolestes belongs to ... . Not only were Necrolestes and Necrolestes found to have remarkable similarities, they are the only known mammals to have single-rooted molars—most mammals have double-rooted molars.

I admit to being confused. Did somebody global replace another scientific name with Necrolestes? or what? And how about that "they are the ONLY known mammals ... -- MOST mammals ..."

Get some editors physorg.

Yes...the wording is confusing. They talk about Necrolestes patagonensis in the beginning, but then they say "Enter Necrolestes".
Oh OK...here it is.

"The mystery solved In 2011, a newly discovered extinct mammal named Necrolestes was the key that unlocked the mystery of the burrowing enigma. Discovered by co-author Rougier in South America, Necrolestes belongs to the Meridiolestida, a little-known group of extinct mammals found in the Late Cretaceous and early Paleocene (100 million years ago) of South America. Not only were Necrolestes and Necrolestes found to have remarkable similarities"

The first one was found in Patagonia in 1891, and the latest one was found by Rougier in 2011. They now have 2 fossils of the same species.

Yes...the wording is confusing. They talk about Necrolestes patagonensis in the beginning, but then they say "Enter Necrolestes".
Oh OK...here it is.

"The mystery solved In 2011, a newly discovered extinct mammal named Necrolestes was the key that unlocked the mystery of the burrowing enigma. Discovered by co-author Rougier in South America, Necrolestes belongs to the Meridiolestida, a little-known group of extinct mammals found in the Late Cretaceous and early Paleocene (100 million years ago) of South America. Not only were Necrolestes and Necrolestes found to have remarkable similarities"

The first one was found in Patagonia in 1891, and the latest one was found by Rougier in 2011. They now have 2 fossils of the same species.

Actually, the same story is on discovery.com, just better written. It isn't 2 fossils of the same species. A different species with a different scientific name was found in 1911. That website also kept the "only" - "most" problem, though