The early development of lepas. A study of cell-lineage and germ-layers

Evolutionary Developmental Biology of Invertebrates 4

“…2.2 and boxed text herein), and it was broadened to other crustacean taxa of Copepoda, Cirripedia, and Dendrobranchiata (Bigelow 1902 ;Amma 1911 ;Fuchs 1914 ;Delsman 1917 ;Zilch 1978 ). 2.2 and boxed text herein), and it was broadened to other crustacean taxa of Copepoda, Cirripedia, and Dendrobranchiata (Bigelow 1902 ;Amma 1911 ;Fuchs 1914 ;Delsman 1917 ;Zilch 1978 ).…”

“Crustacea”: Cirripedia

“…The search was therefore on for arthropods that showed signs of an annelid-type spiral cleavage in their embryology, since this might shed light on the origin of the taxon. Many cirripedes have a holoblastic cleavage that is very amenable to the analysis of cleavage patterns, and early papers argued that there were clear signs of a spiral pattern in the embryology of some thoracican species (Bigelow 1902 ;Delsman 1917 ). In a very detailed and authoritative account, Anderson ( 1969 ) challenged many of these interpretations although he still operated under the assumption of 'an annelid ancestry' of arthropods.…”

“Crustacea”: Comparative Aspects of Early Development

“…2.2 and boxed text herein), and it was broadened to other crustacean taxa of Copepoda, Cirripedia, and Dendrobranchiata (Bigelow 1902 ;Amma 1911 ;Fuchs 1914 ;Delsman 1917 ;Zilch 1978 ). Since the turn of the millennium, new data were added for the Dendrobranchiata, Caridea, Euphausiacea, Branchiopoda, and Amphipoda.…”

“…Most other malacostracans have superficial cleavage and the mesoderm is positioned anterior of the endoderm. Data are based on ( A ) the malacostracan amphipod Parhyale , ( B ) thecostracan barnacles (Bigelow 1902 ;Shiino 1957 ), ( C ) the malacostracan shrimps (Kajishima 1952 ;Hertzler 2002 ), ( D ) a copepod (Fuchs 1914 ; the relationship between the anterior-posterior axis and the endoderm and germ line that is shown here is modeled after other crustaceans), and ( E ) branchiopodan water fl eas (Grobben 1879 ;Kühn 1913 ) Copepoda, Cirripedia, Dendrobranchiata, and Amphipoda sit dispersed within the crustacean's phylogenetic tree, and the taxa in between show superfi cial cleavage. The taxa with invariant early lineages sit nested within taxa that lack this trait, and assuming multiple origins requires fewer steps than the opposite assumption of a single origin.…”