Evolutionary Relationships

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Outline

• Evolutionary Relationships
• Acoelomates (sort of)
• Phylum Platyhelminthes
• Phylum Nemertea
• Gnathiferans
• Phylum Rotifera
• Phylum Acanthocephala

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Evolutionary Relationships I
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Evolutionary Relationships II
CHARACTERISTICS OF THE BILATERIA
1) Bilateral symmetry
-- mirror images about sagittal plane
2) triploblastic
-- embryonic mesoderm is present
3) separate mouth and anus
-- digestive tract is complete exceptions among
acoelomates
4) cephalization
-- most have a distinguishable head
5) organ/system grade of organization
-- some simple organ systems
6) primitively protostomous

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Evolutionary Relationships III
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Phylum Platyhelminthes Introduction
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Platyhelminthes Distinguishing Characteristics I
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Platyhelminthes Distinguishing Characteristics II
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Platyhelminthes Distinguishing Characteristics
III
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Platyhelminthes Distinguishing Characteristics IV
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Platyhelminthes Distinguishing Characteristics V
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Platyhelminthes Major Groups
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Platyhelminthes Class Turbellaria
A. Sanchez-Alvarado
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Taenia taeniaeformis BioLib
Platyhelminthes Class Cestoda I
BBC
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Platyhelminthes Class Cestoda II
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Platyhelminthes Class Cestoda III
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Platyhelminthes Class Monogenea
M. Faasse
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Platyhelminthes Class Trematoda I
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Platyhelminthes Class Trematoda II
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NOAA
Phylum Nemertea Introduction
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Nemertea Distinguishing Characteristics I
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Nemertea Distinguishing Characteristics II
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Gnathiferans Phylum Rotifera
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Gnathiferans Phylum Acanthocephala