• Sargocentron spiniferum (Forsskål, 1775) grootdoorneekhoornvis
  sabre squirrelfish
  
• Saxifraga granulata L. knolsteenbreek
  meadow saxifrage
  
• Scapharca diluvii (Lamarck, 1805)
• scapoliet scapoliet
  scapolite
  
• Scarabaeus sennaariensis (Castelnau, 1840) scarabee
  scarab
  
• Scarus ghobban Forsskål, 1775 blauwbandpapegaaivis
  blue-barred parrotfish
  
• Schizodactylus monstrosus (Drury, 1773) zandkrekel
  maize cricket
  
• Schizopora paradoxa (Schrad.) Donk witte tandzwam
  
• Schnella guianensis Aubl. schildpadladder
  monkey ladder liana
  
• Sciurus carolinensis Gmelin, 1788 grijze eekhoorn
  eastern gray squirrel
  
• Sciurus vulgaris Linnaeus, 1758 rode eekhoorn
  red squirrel
  
• Sclerocephalus haeuseri Goldfuss 1847 amfibie
  amphibian
  
• Sclerothamnus clausi Marshall, 1875 glasspons
  glass sponge
  
• Scophthalmus rhombus (Linnaeus, 1758) griet
  brill
  
• scoria scoria
  scoria
  
• Scorzoneroides autumnalis (L.) Moench vertakte leeuwentand
  fall dandelion
  
• Scrophularia nodosa L. knopig helmkruid
  figwort
  
• Scyliorhinus canicula (Linnaeus, 1758) hondshaai
  small-spotted catshark
  
• Sebastes norvegicus (Ascanius, 1772) roodbaars
  rose fish
  
• Secale cereale L. rogge
  rye
  
• Seirocrinus subangularis (Miller, 1821) zeelelie
  sea lily
  
• Selaginella lepidophylla (Hook. & Grev.) Spring valse roos van Jericho
  false rose of Jericho
  
• Semicassis miolaevigata (Sacco,1890)
• Semionotus capensis (Woodward, 1888) kaaimansnoek
  Semionotus
  
• Semiotus intermedius Herbst, 1806 kniptor
  click beetle
  
• Senna alexandrina Mill. sennapeul
  Alexandrian senna
  
• Senna sp. Senna
  Senna
  
• Sepia officinalis Linnaeus 1758 zeekat
  common cuttlefish
  
• Sequoiadendron giganteum (Lindl.) J.Buchh. mammoetboem
  giant sequoia
  
• Serinus serinus (Linnaeus, 1766) Europese kanarie
  European serin
  
• Serpula vermicularis Linnaeus, 1767 kleine kalkkokerworm
  calcareous tubeworm
  
• sfaleriet sfaleriet
  sphalerite
  
• Sidneyia inexpectans Walcott, 1911 primitieve geleedpotige
  primitive arthropod
  
• Siganus javus (Linnaeus, 1766)
• Sigillaria hexagona Brongniart zegelboom
  lycopsid
  
• Silurus glanis Linnaeus, 1758 meerval
  wels catfish
  
• sinhalite sinhaliet
  sinhalite
  
• Sinustrombus latissimus (Linnaeus, 1758) brede vleugelslak
  widest Pacific conch
  
• Siphlonurus armatus Eaton, 1870 eendagsvlieg
  mayfly
  
• Sipunculus nudus Linnaeus, 1766 pindaworm
  peanut worm
  
• Sitta frontalis Swainson, 1820 pluchekapboomklever
  velvet-fronted nuthatch
  
• Sloanea sp.
• smaragd smaragd
  emerald
  
• Smaug giganteus (Smith, 1884) reuzengordelstaarthagedis
  giant girdled lizard
  
• Smilodon fatalis (Leidy, 1868) sabeltandkat
  saber-toothed cat
  
• sodaliet sodaliet
  sodalite
  
• Somateria mollissima (Linnaeus, 1758) eider
  common eider
  
• Somateria spectabilis (Linnaeus, 1758) koningseider
  king eider
  
• Sorex araneus (Linnaeus, 1758) bosspitsmuis
  common shrew
  
• Sorex minutus (Linnaeus, 1766) dwergspitsmuis
  pygmy shrew