Atheism is unreasonable

[Anomalocaris]

Minor quibble, Shared primitive trait, such as egg laying, does not denote close evolutionary relationship. Only shared derived trait can be an indication of closeness in relationships.

Birds and earliest mammals clearly share few true common derived traits, and those which they might superficially appear to share, like endothermy and insulating body coverings, are clearly derived separately through convergent evolution, and do not share the same derivation.

So early mammals are not closely related to birds at all. The earliest mammals are already separated from birds by 150-200 million years of independent evolution from carboniferous era (or earlier) onwards, along two widely separated evolutionary lineages. So Platypus, only ~150 million years separated from humans, is already as different from any birds as humans are from platypus.

Your right about the birds. But it is much closer to reptiles. It's the DNA from whence the traits come that matters:

World's Strangest Creature? Part Mammal, Part Reptile
Jeanna Bryner | May 06, 2008 08:00pm ET
The platypus sports a patchwork of features from mammals, reptiles and birds.
Credit: Zina Deretsky, National Science Foundation.
View full size image

The platypus sports fur like a mammal, paddles its duck feet like a bird and lays eggs in the manner of a reptile.

Nature's instruction manual for this oddball, it turns out, is just as much of a mishmash.

Researchers just mapped the genome of a female platypus from Australia. The genetic sequence of this Aussie monotreme (a type of mammal) is detailed in the May 8 issue of the journal Nature.

"The platypus is a very ancient offshoot of the mammal tree, so it was 166 million years ago that we last shared a common ancestor with platypuses," said study team member Jenny Graves, head of the Comparative Genomics Group at the Australian National University. "And that puts them somewhere between mammals and reptiles, because they still maintain quite a lot of reptilian characteristics that we’ve lost, for instance they still lay eggs."

She added, "So we can use them to trace the changes that have occurred as we went from being a reptile, to having fur to making milk to having live-born young."

http://www.livescience.com/7488-world-st...ptile.html

Unfortunately, the article chose to use somewhat obsolete term reptile to exploit a popular, but obsolete understanding and land vertebrate classification.

Traditional classifications say all air breathing quadrupedal vertebrate animals which lay hard shell eggs, has or were thought to have scaly skin and cold blood were more closely related to each other than to other groups of air breathing vertebrates, and formed a natural grouping.

Modern genetic and cladistic analysis shows traditional "reptile" do not form a natural, closely related group. Instead it is made up of 3, possibly 4 widely separated lineages, 2 of these lineages are more closely related to other groups not traditionally considered to be reptiles - birds and mammals respectively - than they each are to other lineages within the traditional reptile group.

So the best that could be said for the comparison made in the article is yes, platypus laid eggs and lad scales. So what? What group of "reptiles" is platypus actually similar to? And what are they like? As it turns out, the group the "reptiles" platypus is most closely related to and similar to are the selves remarkably mammal like. If you see one alive, you would surely call it a furry critter, and would never call it reptile. That group of animals had fur, was almost certainly warm blooded, often had dog like dentition and many had a dog like face, and all had a distinctly mammal like upright walk, not sprawled like our usual notion of reptiles at all. Sure, they also laid eggs, and at least early members would not have nursed, so they would not be called mammals. But at first sight they would sure as hell fool most people into thinking they were mammals.

Is it any wonder primitive mammal platypus should be very close to "reptiles" which are so uncannily Mammal like in the first place?

The point is there is no abrupt transition from mammalian ancesters (traditionally called mammal like reptiles) to mammals. The process is gradual. Every part of mammal lineage is close to its immediate ancester. Even humans are closer to later mammal like reptiles than those mammal like reptiles are to crocodiles or turtles. Mammalian traits accumulated over a long time, at least 100 million years. The earliest synapsid (the proper name for the lineage, formerly assigned to reptiles, which are ancesteral to mammals) is 300+ million years old. It already had distinctive features which sets it apart from any other "reptile" and mark it as an early relation of the mammal family.