Phylum Chordata - Chordates Internal skeleton with muscle ...

More documents

Recommendations

Info

Modern Mammalsnineteen ordersSeventeen are placental mammalsTwo are non-placental mammals :monotremes and marsupialsMonotremes - Egg-laying mammalsIncludes duck-billed platypus and two species of echidnaMonotremes retain some reptilian characteristicsLay shelled eggs which they incubate in a nestShoulder and pelvic bones similar to early reptilesHave a cloaca - a single opening for feces, urine, and eggsMore closely related to early extinct mammalsHave functioning mammary glandsMarsupials - Pouched-mammalsMarsupial fertilized egg is amniotic but lacks shellMarsupial egg has much yolk to nourish embryoEmbryonic marsupial is born early in developmentCrawls to marsupial pouch, attaches to nipple, continues todevelop for monthsNearly all modern marsupials live inAustralia and New GuineaOnly 20 of 280 total species liveelsewhereMarsupials in Australia and NewGuinea fill niches that placentalmammals fill elsewhereVirginia opossum is the only marsupialin North America
Placental mammalsHave well-developed placentathat nourishes embryosfor entire developmentEggs have little yolkPlacenta forms early in courseof developmentEmbryos develop in uterus (womb)of motherFetal placenta formed fromchorion and allantoisMaternal placenta formed fromwall of uterusYoung undergo considerabledevelopment before birthMany have extensive parental care
Page 4 and 5: The defining chordate characteristi
Page 6 and 7: The vertebrates are composed of eig
Page 9 and 10: Sharks became dominant predators ab
Page 11 and 12: Class Amphibia - Amphibiansincludes
Page 13 and 14: Modern AmphibiansOrder Anura - frog
Page 15 and 16: Dry skin with scales or armor reduc
Page 17 and 18: Dinosaurs - greater agilityLegs pos
Page 19 and 20: Other Important Characteristics of
Page 21 and 22: Class Aves - BirdsMost successful o
Page 23 and 24: Efficient circulationHas four-chamb
Page 25 and 26: Characteristics of Modern MammalsEn
Page 27: Hooves, Horns, and Antlersclaws, fi

Phylum Chordata - Chordates Internal skeleton with muscle ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?