Brachiopoda sunt animalia nonnisi marina, immobilia, quorum corpus inter organa principalia lophophorum (coronam tentaculorum) habet et concha e duabus valvis inaequalibus consistente tegitur. In taxinomia biologica tamquam phylum habentur.[1] Brachiopoda hodierna pauca sunt, circa 100 genera cum circa 400 speciebus;[2] attamen numerus generum brachiopodorum fossilium plus quam 4200 est.[3]

Lingula anatina, brachiopus linguliforme inarticulatum

Animalia — Brachiopoda
Duméril, 1806
   
Palaeontologia
Lower Cambrian–Recent
Subdivisiones: Subphyla et classes

Historia investigationis recensere

 
Terebratalia transversa, brachiopodum hodiernum, litus Californiae in Oceano Pacifico habitat.

Nomen brachiopodorum e vocabulis Graecis βραχίων ‘brachium’ et πούς ‘pes’ compositum est, propter opinionem erroneam brachia lophophori extensibiles esse, iisque a brachiopodis tamquam pedibus ad gradiendum uti.[4] Hoc nomen Andreas Maria Constans Duméril zoologus anno 1805 introduxit.[5] Antea Brachiopoda inter Mollusca annumerabantur, ut puta apud Linnaeum.

Cum brachiopoda fossilia multo plura hodiernis sint, a palaeontologis praesertim investigantur, rarius autem a zoologis.[6] Brachiopodologi congressum primum anno 1985 Brestiae celebraverunt; anno 2018 octavus congressus brachiopodologicus Mediolani habitus est.[7]

Ad brachiopoda investiganda structurae eorum interiores, quae in fossilibus plerumque visui non apparent, revelandae sunt. Unde frequenter brachiopodorum conchae fossiles in substantia abrasiva a palaeontologis teruntur poliunturque, quo fit, ut structurae interiores conchae observari possint, sed in fine concha destruitur. Quod methodus sectionum serialium dicitur.[8][9]

Descriptio recensere

 
Brachiopoda hodierna

Concha recensere

Concha (seu testa[10]) brachiopodorum e duabus valvis consistit, ideo conchae Molluscorum bivalvium (seu Lamellibranchiatorum) vel nonnullorum Arthropodorum (ut Ostracodorum vel Conchostracorum) similis est. Attamen apud Mollusca et Arthropoda ambae valvae symmetricae sunt respectu plani symmetriae inter eas siti (ideoque valva sinistra et dextra dicuntur); e contra, valvae conchae Brachiopodorum inaequales sunt, quarum una minor dorsalis vel brachialis dicitur, altera maior autem ventralis vel peduncularis. Planum symmetriae conchae brachiopodorum perpendiculare respectu plani inter valvas siti est.[11]

Conchae brachiopodorum plerumque parvae sunt; brachiopodum omnium maximum, Gigantoproductus dictum, tempore Carbonifera vivens, usque ad 37.5 cm tantum crescebat.[12] Conchae brachiopodorum tum e carbonate calcii, tum e phosphate fiunt.[13]

Corpus recensere

Inter organa principalia brachiopodorum lophophorus, pallium et pedunculus habentur. Lophophorus corona tentaculorum est et semper cavum interius coelomaticum habet; ad vescendum animali servit, qui eo ad colligendas particulas parvas quae in aqua maris inveniuntur (exempli gratia diatomeas) utitur. A pallio, totum corpus molle brachiopodi operiente, concha exhalatur. Pedunculus, qui non semper adest, trans foramen pedunculare e concha exiens, eandem in substrato stabilit.[12]

Evolutio recensere

Brachiopoda inter alia phyla animalium recensere

Brachiopoda, bryozoa, et phoronida lophophorum habent, quod cognationem eorum arctam demonstrat, unde haec tria phyla in superphylum Lophophoratorum iunguntur.[1] Yuganotheca, animal periodi Cambriae ad Chengjiang in Sina inventum, proprietates brachiopodorum phoronidorumque simul exhibet.[14] Lophophorata subdivisio Lophotrochozoorum, Lophotrochozoa (ad quae Annelida et Mollusca pertinent) subdivisio Protostomiorum est.[1]

Historia brachiopodorum recensere

Brachiopoda antiquissima in stratis stadii secundi Cambrii reperiuntur,[14] sunt ergo antiquiores trilobitis nonnisi in stadio tertio apparentium.[15] Per totam aeram Palaeozoicam brachiopoda inter animalia in maris frequentissima inveniebantur. In Devonio oecosystemata brachiopodeta dicta aderant, tamquam prata marina a permultis brachiopodis obsita. In Permio brachiopoda quaedam scopulos aedificabant, ut hodie anthozoa. Post catastrophen quae Palaeozoicum a Mesozoico (scilicet Permium a Triassico) separat brachiopoda paulatim rariora facta sunt. In iisdem oecosystematibus, ubi in Palaeozoico brachiopoda molluscis bivalvibus frequentiora fuerunt, in Mesozoico et Caenozoico bivalvia plura quam brachiopoda sunt.[16]

Notae recensere

  1. 1.0 1.1 1.2 Giribet, G. & Edgecombe, G. D. (2020), The Invertebrate Tree of Life (Princeton–Oxford: Princeton University Press, ISBN 9780691170251).
  2. Ye, F., Shi, G. R. & Bitner, M. A. (2021), "Global biogeography of living brachiopods: Bioregionalization patterns and possible controls," PLoS ONE 16 (11): e0259004.
  3. Curry, G.B. & Brunton, C.H.C. (2007), "Stratigraphic distribution of brachiopods" in Selden, P. (ed.), Treatise on Invertebrate Paleontology, Part H, Brachiopoda (retractata), 6: 2901–3081 (Boulder–Lawrence: Geological Society of America & University of Kansas Press).
  4. Muir-Wood, H.M., 1955. A history of the classification of the phylum Brachiopoda. British Museum (Natural History), London.
  5. Duméril, A.-M. C. 1805. Zoologie analytique, ou méthode naturelle de classification des animaux, rendue plus facile à l’aide de tableaux synoptiques. Allais, Paris. [‘1806’; de anno editionis vide Gregory, 2010, Zoological Bibliography 1(1): 6–8.].
  6. Carlson, S., 2016. The Evolution of Brachiopoda. Annual Review of Earth and Planetary Sciences, 44: 409-438.
  7. Halamski, A.T., 2019. Eighth International Brachiopod Congress Milan, Italy, 11th-14th September, 2018. http://paleopolis.rediris.es/BrachNet/REF/Pub/halamski-2019.html
  8. Sollas, W.J., 1904. A method for the investigation of fossils by serial sections. Philospohical Transactions of the Royal Society of London, Series B, 196: 259–265
  9. Croft, W.N., 1950. A parallel grinding instrument for the investigation of fossils by serial sections. Journal of Paleontology, 24: 693–698.
  10. Nilsson, S., 1827. Petrificata Suecana formationis cretaceae, descripta et iconibus illustrata. Pars prior, Vertebrata et Mollusca sistens. Officina Berlingiana, Londini Gothorum.
  11. Roger, J., 1960. Brachiopodes fossiles. 1431–1499. In: Grassé, P.-P. (ed.), Traité de Zoologie. Tome V, fasc. 2. Masson, Paris.
  12. 12.0 12.1 Hyman, L.H., 1959. The Invertebrates. Volume V: Smaller coelomate groups. McGraw-Hill, New York–London–Toronto.
  13. Cusack, M., Walton, D. & Curry, G.B., 1997. Shell biochemistry. 243–266. In: Kaesler, R.L. (ed.), Treatise on Invertebrate Paleontology, Part H, Brachiopoda (revised), Volume 1. Geological Society of America & University of Kansas Press, Boulder–Lawrence.
  14. 14.0 14.1 Harper, D.A.T., Popov, L.E. & Holmer, L.E., 2017. Brachiopods: origin and early history. Palaeontology, 60 (5): 609-631.
  15. Holmes, J. D. & Budd. G. E., 2022. Reassessing a cryptic history of early trilobite evolution. Communications Biology, 5: 1177. https://doi.org/10.1038/s42003-022-04146-6.
  16. Gould, Stephen J. & Calloway, C. B., 1980. Clams and brachiopods—ships that pass in the night. Paleobiology, 6 (4): 383-96.

Bibliographia recensere

  • Kaesler, R., ed. 19972006. Treatise on Invertebrate Paleontology. Part H, Brachiopoda (revised). Vol. 1 (1997), vols 2–3 (2000), vol. 4 (2002), vol. 5 (2006). Geological Society of America & University of Kansas Press.
  • Rudwick, M. J. S. 1970. Living and fossil brachiopods. Hutchinson University Library, London.
  • Selden, P., ed. 2007. Treatise on Invertebrate Paleontology. Part H, Brachiopoda (revised). Vol. 6. Geological Society of America & University of Kansas Press.