Research article
Evidence for gill slits and a pharynx in Cambrian vetulicolians: implications for the early evolution of deuterostomes
1 Early Life Evolution Laboratory, School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China
2 Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK
3 Early Life Institute and Key Laboratory of Continental Dynamics, Northwest University, Xi'an 710069, China
4 Chengjiang Fauna National Geopark of China, Chengjiang 652500, China
BMC Biology 2012, 10:81 doi:10.1186/1741-7007-10-81
Published: 2 October 2012Additional files
Additional file 1:
Gill structures of Vetulicola rectangulata from Yunnan, China. (A,B) Laterally preserved specimens ELEL-SJ101975A and ELEL-EJ080158A, respectively. (C,D) Close-up images of the boxed area in (A) and interpretative camera lucida drawing, respectively, showing gill openings, lateral groove, groove floor, Y-shaped medial gutters, transverse ridge posterior of the gill pore, lappets, and their spatial arrangement relative to the adjacent plates. (E,F) Close-up images of boxed area in (B) and interpretative camera lucida drawing, respectively, showing dilated lateral groove, groove floor, Y-shaped medial gutters, gill openings, lappets, and their spatial relationship. Abbreviations: Cz, concentric zone that surrounds the gill opening; G1-5, gills 1 to 5; Go, gill opening; La, lappet; Po, gill pouch; Rg, ridge; Se, sediment fill; Tf, trace fossil (unconnected to specimen); Tr, trough; Ys, Y-shaped structure. Scale bars: 1 cm in (A), (B); 5 mm in (C) to (F).
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Additional file 2:
Linear statistics of gill geometry of Vetulicola. (A-E) Linear regression of gill pouch width on gill slit diameter (gills 1 to 5, respectively), measured from 130 well-preserved gills in 37 specimens of Vetulicola rectangulata (data source: Additional file 3) using PAST software [59], showing the correlation between gill slit diameter and gill pouch width (r: correlation coefficiency).
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Additional file 3:
Morphometrics of vetulicolian gills. Morphometrics of vetulicolian gills given in mm.
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Additional file 4:
Gill filaments in Vetulicola cuneata from Yunnan, China. (A) Laterally preserved specimen ELI-0000216. (B) Close-up image of the boxed area in (A), displaying tufts of filaments lining the surface of the gill pouch (viewed from the exterior). Transverse, slit-like gill opening denoted by arrowhead. Abbreviations: Fi, filaments; G1-5, gills 1 to 5; La, lappet; M, mouth; T, tail; Tr, trough. Scale bars: 1 cm in (A), (B); 5 mm in (C) to (F).
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