- Title Pages
- Preface to third edition
- Preface to second edition
- Preface to first edition
- 1 Introduction
- 2 ANIMALIA (METAZOA)
- 3 Prelude: Phylum Choanoflagellata
- 4 Early animal radiation
- 5 Phylum Silicea
- 6 EURADICULATA
- 7 <i>Phylum</i> Calcarea
- 8 PROEPITHELIOZOA
- 9 <i>Phylum</i> Homoscleromorpha
- 10 EUMETAZOA (GASTRAEOZOA)
- 11 <i>Phylum</i> Placozoa
- 12 NEURALIA
- 13 <i>Phylum</i> Cnidaria
- 14 TRIPLOBLASTICA
- 15 Phylum Ctenophora
- 16 BILATERIA
- 17 ACOELOMORPHA
- 18 Phylum Acoela
- 19 Phylum Nemertodermatid
- 20 <i>Phylum</i> Xenoturbellida
- 21 EUBILATERIA
- 22 PROTOSTOMIA
- 23 SPIRALIA (LOPHOTROCHOZOA)
- 24 SCHIZOCOELIA
- 25 Phylum Annelida
- 26 <i>Phylum</i> Sipuncul
- 27 Phylum Mollusca
- 28 <i>Phylum</i> Nemertin
- 29 <i>Phylum</i> Platyhelminthes
- 30 Phylum Gastrotricha
- 31 GNATHIFERA
- 32 <i>Phylum</i> Gnathostomulida
- 33 <i>Phylum</i> Micrognathozoa
- 34 <i>Phylum</i> Rotifera
- 35 POLYZOA (BRYOZOA s.l.)
- 36 Phylum Entoprocta
- 37 <i>Phylum</i> Cycliophora
- 38 Phylum Bryozo (Ectoprocta)
- 39 BRACHIOZOA
- 40 <i>Phylum</i> Phoronida
- 41 <i>Phylum</i> Brachiopoda
- 42 ECDYSOZOA
- 43 PANARTHROPODA
- 44 <i>Phylum</i> Arthropoda
- 45 <i>Phylum</i> Onychophora
- 46 <i>Phylum</i> Tardigrada
- 47 CYCLONEURALIA
- 48 NEMATOIDEA
- 49 <i>Phylum</i> Nematoda
- 50 <i>Phylum</i> Nematomorpha
- 51 SCALIDOPHORA
- 52 <i>Phylum</i> Priapul
- 53 <i>Phylum</i> Kinorhynch
- 54 <i>Phylum</i> Loricifera
- 55 <i>Phylum</i> Chaetognatha
- 56 DEUTEROSTOMIA
- 57 AMBULACRARIA
- 58 <i>Phylum</i> Echinodermata
- 59 HEMICHORDATA
- 60 <i>Phylum</i> Enteropneusta
- 61 <i>Phylum</i> Pterobranchia
- 62 CHORDATA
- 63 <i>Phylum</i> Cephalochordata
- 64 <i>Phylum</i> Urochordata
- 65 <i>Phylum</i> Vertebrata (Craniata)
- 66 Problematica
- Systematic index
- Subject index
- Plates
ANIMALIA (METAZOA)
ANIMALIA (METAZOA)
- Chapter:
- (p.7) 2 ANIMALIA (METAZOA)
- Source:
- Animal Evolution
- Author(s):
Claus Nielsen
- Publisher:
- Oxford University Press
In Systema Naturæ (1735, 1758), Carolus Linnaeus proposed a definition of the Kingdom Animalia: natural objects that grow, live, and sense. In contrast, plants grow and live but do not sense, while minerals grow but do not live or sense. In this definition of the animal kingdom, species are arranged in classes, families, and genera. This division of organisms into animals and plants was almost unchallenged for more than 100 years. In 1866, Ernst Haeckel came up with the first classification of living beings based on Charles Darwin’s ideas on evolution. He separated the Kingdom Animalia from the new Kingdom Protista based on the possession of tissues and organs. Today, the animal kingdom is restricted to multicellular animals, that is, the Metazoa. This chapter provides an overview of metazoans, including their apomorphies, sexual reproduction and life cycle, and genes involved in organising the metazoan body. It also describes some of the metazoan morphological characters, including cilia and flagella, choanocytes, cell junctions and epithelia.
Keywords: animal kingdom, Metazoa, apomorphies, sexual reproduction, genes, cilia, flagella, choanocytes, cell junctions, epithelia
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- Title Pages
- Preface to third edition
- Preface to second edition
- Preface to first edition
- 1 Introduction
- 2 ANIMALIA (METAZOA)
- 3 Prelude: Phylum Choanoflagellata
- 4 Early animal radiation
- 5 Phylum Silicea
- 6 EURADICULATA
- 7 <i>Phylum</i> Calcarea
- 8 PROEPITHELIOZOA
- 9 <i>Phylum</i> Homoscleromorpha
- 10 EUMETAZOA (GASTRAEOZOA)
- 11 <i>Phylum</i> Placozoa
- 12 NEURALIA
- 13 <i>Phylum</i> Cnidaria
- 14 TRIPLOBLASTICA
- 15 Phylum Ctenophora
- 16 BILATERIA
- 17 ACOELOMORPHA
- 18 Phylum Acoela
- 19 Phylum Nemertodermatid
- 20 <i>Phylum</i> Xenoturbellida
- 21 EUBILATERIA
- 22 PROTOSTOMIA
- 23 SPIRALIA (LOPHOTROCHOZOA)
- 24 SCHIZOCOELIA
- 25 Phylum Annelida
- 26 <i>Phylum</i> Sipuncul
- 27 Phylum Mollusca
- 28 <i>Phylum</i> Nemertin
- 29 <i>Phylum</i> Platyhelminthes
- 30 Phylum Gastrotricha
- 31 GNATHIFERA
- 32 <i>Phylum</i> Gnathostomulida
- 33 <i>Phylum</i> Micrognathozoa
- 34 <i>Phylum</i> Rotifera
- 35 POLYZOA (BRYOZOA s.l.)
- 36 Phylum Entoprocta
- 37 <i>Phylum</i> Cycliophora
- 38 Phylum Bryozo (Ectoprocta)
- 39 BRACHIOZOA
- 40 <i>Phylum</i> Phoronida
- 41 <i>Phylum</i> Brachiopoda
- 42 ECDYSOZOA
- 43 PANARTHROPODA
- 44 <i>Phylum</i> Arthropoda
- 45 <i>Phylum</i> Onychophora
- 46 <i>Phylum</i> Tardigrada
- 47 CYCLONEURALIA
- 48 NEMATOIDEA
- 49 <i>Phylum</i> Nematoda
- 50 <i>Phylum</i> Nematomorpha
- 51 SCALIDOPHORA
- 52 <i>Phylum</i> Priapul
- 53 <i>Phylum</i> Kinorhynch
- 54 <i>Phylum</i> Loricifera
- 55 <i>Phylum</i> Chaetognatha
- 56 DEUTEROSTOMIA
- 57 AMBULACRARIA
- 58 <i>Phylum</i> Echinodermata
- 59 HEMICHORDATA
- 60 <i>Phylum</i> Enteropneusta
- 61 <i>Phylum</i> Pterobranchia
- 62 CHORDATA
- 63 <i>Phylum</i> Cephalochordata
- 64 <i>Phylum</i> Urochordata
- 65 <i>Phylum</i> Vertebrata (Craniata)
- 66 Problematica
- Systematic index
- Subject index
- Plates