Be careful what you ask for. :-)
From what I've found monotremes are egg-laying mammals, of which two creatures exist: platypus and echidna (spiny anteater). You mentioned obdurodon insignis as the species from which the 11 traits of the platypus descended.
A search on obdurodon insignis returned the same site Junior listed. This site states:
The oldest fossil monotremes come from the Lightning Ridge opal fields of New South Wales, Australia. An opalized lower jaw fragment of Steropodon galmani more than 100 million years old (middle Albian, Cretaceous) was found containing three distinctive teeth remarkably similar to those of the juvenile platypus. From the size of the jaw, it is estimated that the living animal was about the size of a cat, making it one of the largest Mesozoic mammals known. This find (Archer et al. 1985) marked the first known Australian mammal from the Mesozoic. A second jaw, described as Kollikodon ritchiei, was found in 1995 from deposits of similar age, suggesting that monotremes had already diversified by the Early Cretaceous.
During the 1970s, the first Tertiary monotreme fossils were uncovered in southern Australia. Over several years, a jaw, a pelvis, and teeth of the Miocene platypus Obdurodon insignis were discovered. A cast of Obdurodon teeth is pictured above.
The site then continues talking about a different species, O. dicksoni:
More recently, a skull with a nearly full complement of teeth has been found in New South Wales (Archer et al. 1992). This new species, O. dicksoni, demonstrates that unlike the modern platypus, Obdurodon kept its teeth at maturity. Like the platypus, however, Obdurodon had an elongated snout, though straighter than in its modern relative. Opinions differ on whether Obdurodon may have been aquatic, based on its association with numerous terrestrial marsupials.
I could not find anything that said Obdurodon insignis had the 11 traits previously listed. It also appears gore3000 read the link or was already familiar with the evidence as he said: Can you give us a picture of this obduron insignis? Can you show us the traits he had? Of course not, because it is only a lower jaw. Of course there is the two teeth from South America proving the descent of this toothless animal also! I am asking for a species we know had the traits, not a couple of bones. There are a million species around from all classes of vertebrates, none of which have even a small portion of the traits of the platypus.
Which aligns with my own research which includes the link from Junior.
Since Obdurodon insignis doesn't fill the requirements, do you have a URL or any information that provides for a species from which the platypus descended with the 11 traits gore3000 requested? BTW, you did say:
Okay, here's an answer, and you two can try to prove me wrong.
For what it's worth, I'm really trying to be objective here and not misrepresent anything found in my own research.