1.
Naturwissenschaften
; 88(6): 268-72, 2001 Jun.
Artigo
em Inglês
| MEDLINE
| ID: mdl-11544954
RESUMO
Fossil spermatozoa are recorded for the first time in freshwater ostracods (small bivalved crustaceans) from Holocene sediments at sites in the United Kingdom and Germany. Exceptional conditions at these sites have resulted in the preservation of chitinous "soft parts", including limbs, the remains of Zenker's Organs (sperm pumps that are part of the male reproductive apparatus in cypridoidean ostracods) and spermatozoa from eight different species. Comparisons are made with spermatozoa from living ostracods and the implications of these discoveries for evolutionary studies of reproductive modes are discussed.
Assuntos
Crustáceos/fisiologia , Crustáceos/ultraestrutura , Fósseis , Espermatozoides/ultraestrutura , Animais , Quitina/análise , Água Doce , Sedimentos Geológicos , Alemanha , Masculino , Microscopia Eletrônica de Varredura , Reino Unido
2.
MCN Am J Matern Child Nurs
; 15(4): 232-3, 1990.
Artigo
em Inglês
| MEDLINE
| ID: mdl-2115950