page_title: List of the Paleozoic life of Ohio
section_title: M
hierarchical_section_title: List of the Paleozoic life of Ohio / M
caption_attribution_description: English: Mucrospirifer mucronatus (Conrad, 1841) from the Silica Shale Formation (Middle Devonian) in Paulding County, Ohio. Dorsal valve view.
context_page_description: This list of the Paleozoic life of Ohio contains the various prehistoric life-forms whose fossilized remains have been reported from within the US state of Ohio and are between 541 and 252.17 million years of age.
context_section_description: †Macrerpeton
  †Macrerpeton huxleyi – type locality for species
  †Macrochilina
  †Macrochilina humilis
  †Maelonoceras
  †Manitoulinoceras
  †Manitoulinoceras gyroforme
  †Manitoulinoceras williamsae
   †Manticoceras
  †Manticrinus
  †Manticrinus exaitos
  †Marsupiocrinus
  †Maryonychia
  †Maryonychia concordensis
  †Mastigograptus
  †Mastigograptus strictus
  †Mazostachys
  †Mazostachys compacta – type locality for species
  †Mediospirifer
  †Mediospirifer audaculus
  †Meekopinna
  †Meekopinna americana
  †Meekospira
  †Meekospira peracuta
  †Megacanthopora
  †Megacanthopora fallacis – or unidentified comparable form
  †Megacystites
   †Megalocephalus – type locality for genus
  †Megalocephalus lineolatus – type locality for species
  †Megalograptus
  †Megastrophia
  †Megastrophia concava
  †Megistocrinus
  †Megistocrinus depressus
  †Melocrinus
  †Melocrinus clarkei
  †Meristospira
  †Meristospira michiganensis
  †Merocrinus
  †Mesocoelia
  †Mesocoelia obstipisutura
  †Mesopalaeaster
  †Mesopalaeaster finei
  †Mesopalaeaster wilberanus
  †Mesothyra
  †Mesotrypa
  †Mesotrypa orbiculata
  †Metaxys
  †Metaxys fossa – type locality for species
  †Miamoceras
  †Michelinoceras
  †Micrhystridium
  †Micrhystridium adductum
  †Micrhystridium complurispinosum
  †Micrhystridium erugatum
  †Micrhystridium flexibile
  †Micrhystridium inusitatum
  †Micrhystridium profusam
  †Microceras
  †Microdoma
  †Microdoma tricarinatus
  †Microptychis
  †Microptychis cerithiformis
  †Microptychis expetendus
  †Microptychis occabus – type locality for species
  †Microptychis turbineus
  †Microreticulatisporites
  †Microreticulatisporites harrisonii
  †Microreticulatisporites nobilis
  †Microreticulatisporites sulcatus
  †Milleratia
  †Mitrospermum
  †Mitrospermum vinculum
  †Mixoneura
  †Modiolodon
  †Modiolodon subovalis
  †Modiolopsis
  †Modiolopsis capax
  †Modiolopsis modiolaris
  †Modiolopsis versaillesensis
  Modiolus
  †Modiolus fountainensis
  †Modiolus radiatus – type locality for species
  †Modiolus waverliensis
  †Modiomorpha
  †Modiomorpha concentrica
  †Modiomorpha concentricum
  †Modiomorpha mytiloides
  †Modiomorpha subalata
  †Modiomorpha subalta
  †Molgophis – type locality for genus
  †Molgophis macrurus – type locality for species
  †Monotrypa
  †Monticulipora
  †Mourlonia
  †Mourlonia plena
  †Mourlonia textus
   †Mucrospirifer
  †Mucrospirifer alpenensis
  †Mucrospirifer grabaui – or unidentified comparable form
  †Mucrospirifer mucronatus
  †Mucrospirifer prolificus
  †Multiplicisphaeridium
  †Multiplicisphaeridium anastomosis
  †Multiplicisphaeridium verrucarum
  †Muraticavea
  †Muraticavea enteichia
  †Murchisonia
  †Murchisonia anderdoniae
  †Murchisonia dublinensis – type locality for species
  †Murchisonia gracilicrista
  †Murchisonia intermedia – type locality for species
  †Murchisonia leda
  †Murchisonia minuta
  †Murchisonia sibleyensis
  †Murchisonia subcarinata
  †Murchisonia subulata
  †Myalina
  †Myalina pernaformis
  †Myelodactylus – or unidentified comparable form
  †Mytilarca
  †Mytilarca cordata
caption: Fossilized shell found in Paulding County of the Devonian brachiopod Mucrospirifer
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