1. Platypus Ornithorhynchus anatinus
Whitney Gunn
David Coleman
John Rice

2. Platypus Facts Common Name: Platypus
Scientific Name: Ornithorhynchus anatinus
They live for about 10 to 15 years
Natural habitat is East Australia and New Guinea
Carnivorous diet
Call sound

3. History
Estimate of the Monotremes-Theria divergence, time range between 160 and 120 Myr ago.
The red line shows these are small mammals that developed hair, lactation, and homoeothermic.

4. Characteristics Has spurs on its hind feet
Platypus is one of the few venomous mammals.
The male platypus can delivers a poison through a spur on its hind foot.
Adults do not have teeth
Baby platypus are born with teeth this may be due to a “throwback” from its ancestors. Once they lose them they do not grow new teeth back.
Adults do not need teeth because they use horny pads to grind their food.

5. Characteristics The have no true stomachs Female platypus lay eggs
She lays 1-3 eggs, which she incubates between her abdomen and tail.
Lactation
The female platypus do not have nipples, so it’s young ones suck milk from patches on the abdomen

6. Evolution of Platypus

7. Evolution
Protamine P1 protein sequence

8. Evolution P Distance matrix DNA
Phylogenetic tree showing the relationships between monotremes, marsupials, and mammals
Ech
Mou
Opo
Pla
Roo
0.7162
0.8040
0.7789
0.1030
0.7448
0.8037
0.9769
1.1324
1.2805
0.9405

9. Venomous Trait
The venom is made up of at least 19 different substances
The substance has been named the defensin-like proteins, or DLPs, because their three dimensional structure resembles that of an antimicrobial peptide known as beta-defensin.

10. Lactation and Eggs
It has been proposed that early lactation evolved as a water source to protect porous parchment-shelled eggs from desiccation during incubation or as a protection against microbial infection.
Parchment-shelled egg-laying monotremes also exhibit a more ancestral glandular mammary patch or areola without a nipple that may still possess roles in egg protection

11. Similarities Both are only found in Australia and New Guinea
Monotreme means "one-holed," referring to the cloaca, a single hole that serves the urinary tract, anus, and reproductive tract in monotremes.
Both lay eggs

12. Differences Echidna Platypus Has a point snout Pointy spines on coat
Has duck like bill
Short dark brown fur

13. Further Studies
Recently scientist have been taking the platypus genome and comparing it to humans.
A study on why they secret milk through their abdominal muscles instead of through nipples would be helpful to further understand its evolutionary process.

14. References http://assets0.pubget.com/pdf/8269934.pdf

15. Picture Sources