taxonID	type	format	identifier	references	title	description	created	creator	contributor	publisher	audience	source	license	rightsHolder	datasetID
D864325A597B03547C1C4A726641F960.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/17038460/files/figure.png	https://doi.org/10.5281/zenodo.17038460	Fig. 1 | Jiangfengia multisegmentalis and its visual systems. a Optical photo- graph of of YKLP11117.Its trunk composed of 27 isomorphic segments terminatesin a blade-like telson (TE). The 2 mm scale bar lower right demonstrates the minute- ness of this taxon.The framed area to the right, which includes the carapace and cerebral elements, is enlarged in (b). Within the frame, the upper box indicates the ocellar nature of the anterior sclerite enlarged in Fig.2a–c., the lower box indicates the right eyestalk enlarged in (c, d). b The three rostral-most segments (T1-T3) and the asegmental cephalon are covered by the carapace (CA)extending forward from the anterior margin of the trunk’s (TR) 4th trunk segment (T4). Eyestalks situated behind the paired anterior projections (AP) emerge laterally from the front of the carapace and terminate as compound eyes (right eye RCE, fully exposed, left eye (LCE) mostly buried in the matrix). The midline ‘anterior sclerite’ carries the ocelli (OC, see Fig. 2a–c). c, d Optical photograph with white light and ultraviolet of the enlarged righteyestalk.In c oblique illumination from the right accentuates surface features of the compound retina which is enlarged in the inset lower left.In d mixed white light and ultraviolet reveal facets with missing lenses (center inset) allowing resolution of underlying potential cone cells,as shownin Supplementary Fig.2.The inset lower right schematic demonstrates the hexagonal patterning of ommatidia. e White light optical photograph of the allied multisegmented great appendage euarthropod Fortiforceps showing evidence of a distinct suture (arrowed). Scale bars: a = 2 mm; b = 1 mm; c−e = 50 μm.	Fig. 1 | Jiangfengia multisegmentalis and its visual systems. a Optical photo- graph of of YKLP11117.Its trunk composed of 27 isomorphic segments terminatesin a blade-like telson (TE). The 2 mm scale bar lower right demonstrates the minute- ness of this taxon.The framed area to the right, which includes the carapace and cerebral elements, is enlarged in (b). Within the frame, the upper box indicates the ocellar nature of the anterior sclerite enlarged in Fig.2a–c., the lower box indicates the right eyestalk enlarged in (c, d). b The three rostral-most segments (T1-T3) and the asegmental cephalon are covered by the carapace (CA)extending forward from the anterior margin of the trunk’s (TR) 4th trunk segment (T4). Eyestalks situated behind the paired anterior projections (AP) emerge laterally from the front of the carapace and terminate as compound eyes (right eye RCE, fully exposed, left eye (LCE) mostly buried in the matrix). The midline ‘anterior sclerite’ carries the ocelli (OC, see Fig. 2a–c). c, d Optical photograph with white light and ultraviolet of the enlarged righteyestalk.In c oblique illumination from the right accentuates surface features of the compound retina which is enlarged in the inset lower left.In d mixed white light and ultraviolet reveal facets with missing lenses (center inset) allowing resolution of underlying potential cone cells,as shownin Supplementary Fig.2.The inset lower right schematic demonstrates the hexagonal patterning of ommatidia. e White light optical photograph of the allied multisegmented great appendage euarthropod Fortiforceps showing evidence of a distinct suture (arrowed). Scale bars: a = 2 mm; b = 1 mm; c−e = 50 μm.	2025-08-28	Strausfeld, Nicholas J.;Andrew, David R.;Hou, Xianguang;Hirth, Frank		Zenodo	biologists	Strausfeld, Nicholas J.;Andrew, David R.;Hou, Xianguang;Hirth, Frank			
D864325A597B03547C1C4A726641F960.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/17038465/files/figure.png	https://doi.org/10.5281/zenodo.17038465	Fig. 2 | Morphology of the anterior sclerite indicates an ocellar/nauplius-like “eye” in Jianfengia. a, b Optical photograph and tracing of YKLP11117’s midline anterior sclerite.Despite the compression of thefossil specimen,itreveals concentric arrangements indicating outer dioptric elements interpreted as a triplet of lenses (le) overlying a pigmented layer (pl) beneath which are short columnar elements here interpreted as photoreceptors (re). The entire sclerite arises from a short neck (ne). c UV illumination resolves the neck of the sclerite as comprising fold-like elements suggesting unsclerotized arthrodial membrane (inset lower left) extending from beneath the overlying frontal cuticle (cu). d Optical photograph of specimen YKLP17299 (rendered as monochrome magenta) superimposed on YKLP11117 (monochrome green) to demonstrate the correspondence between neural features and the external morphology of Jianfengia. Ocellar neural pathways (OP) extending to the prosocerebral ocellar neuropils (OCN) indicate that the ocellus (OC) is a bona fide sensory organ supplying the prosocerebrum. Scale bars are 0.25 mm.	Fig. 2 | Morphology of the anterior sclerite indicates an ocellar/nauplius-like “eye” in Jianfengia. a, b Optical photograph and tracing of YKLP11117’s midline anterior sclerite.Despite the compression of thefossil specimen,itreveals concentric arrangements indicating outer dioptric elements interpreted as a triplet of lenses (le) overlying a pigmented layer (pl) beneath which are short columnar elements here interpreted as photoreceptors (re). The entire sclerite arises from a short neck (ne). c UV illumination resolves the neck of the sclerite as comprising fold-like elements suggesting unsclerotized arthrodial membrane (inset lower left) extending from beneath the overlying frontal cuticle (cu). d Optical photograph of specimen YKLP17299 (rendered as monochrome magenta) superimposed on YKLP11117 (monochrome green) to demonstrate the correspondence between neural features and the external morphology of Jianfengia. Ocellar neural pathways (OP) extending to the prosocerebral ocellar neuropils (OCN) indicate that the ocellus (OC) is a bona fide sensory organ supplying the prosocerebrum. Scale bars are 0.25 mm.	2025-08-28	Strausfeld, Nicholas J.;Andrew, David R.;Hou, Xianguang;Hirth, Frank		Zenodo	biologists	Strausfeld, Nicholas J.;Andrew, David R.;Hou, Xianguang;Hirth, Frank			
D864325A597B03547C1C4A726641F960.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/17038471/files/figure.png	https://doi.org/10.5281/zenodo.17038471	Fig. 3 | Reconstructing the brain of Jianfengia. Optical photographs and tracings in (b−h). a Specimen YKLP11367 showing relative sizes of the trunk and cephalic area (boxed). b−h Reconstruction based on hand tracings of fossilized neural traces, neuropils, and connections of specimens YKLP11367, 11368, 11369 and 17299. b To provide a mirror-symmetrical envelope within which neural tracings were mapped, the outline of the right frontal carapace and eyestalk of YKLP11117 was duplicated and flipped over the midline.g All tracings adjusted for axial displacement and mirrored for bilateral symmetry. h Tracings from each specimen filled, made partiallyopaque,and superimposed;themore overlap,the brighter the trace. YKLP11367, 11368, and 11369 provide most of the traces in the eyestalks, flanking the esophageal foramen,and rostral mid-brain.YKLP 17299 provides uninterrupted passage of nerves extending from the anterior sclerite into the prosocerebrum (Fig. 2d). i–q Reconstruction based on computed intensity levels. i Left-right asymmetry of traces reveals partial rotation of YKLP11367 around the antero-	Fig. 3 | Reconstructing the brain of Jianfengia. Optical photographs and tracings in (b−h). a Specimen YKLP11367 showing relative sizes of the trunk and cephalic area (boxed). b−h Reconstruction based on hand tracings of fossilized neural traces, neuropils, and connections of specimens YKLP11367, 11368, 11369 and 17299. b To provide a mirror-symmetrical envelope within which neural tracings were mapped, the outline of the right frontal carapace and eyestalk of YKLP11117 was duplicated and flipped over the midline.g All tracings adjusted for axial displacement and mirrored for bilateral symmetry. h Tracings from each specimen filled, made partiallyopaque,and superimposed;themore overlap,the brighter the trace. YKLP11367, 11368, and 11369 provide most of the traces in the eyestalks, flanking the esophageal foramen,and rostral mid-brain.YKLP 17299 provides uninterrupted passage of nerves extending from the anterior sclerite into the prosocerebrum (Fig. 2d). i–q Reconstruction based on computed intensity levels. i Left-right asymmetry of traces reveals partial rotation of YKLP11367 around the antero-	2025-08-28	Strausfeld, Nicholas J.;Andrew, David R.;Hou, Xianguang;Hirth, Frank		Zenodo	biologists	Strausfeld, Nicholas J.;Andrew, David R.;Hou, Xianguang;Hirth, Frank			
D864325A597B03547C1C4A726641F960.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/17038539/files/figure.png	https://doi.org/10.5281/zenodo.17038539	Fig. 4 | Interpretive reconstruction of Jianfengia multisegmentalis. a Fossil neural traces on the right (blue; scale bar = 0.5 mm) align with arrangements of extant eucrustacean cerebral neuropils (anti-silver-proteinate preparations on left). Optic neuropils of the malacostracan Astacus astacus (Rabbit,polyclonal a-Tubulin, Abcam RRID:AB_301787) match the three nested optic neuropils (ON1-ON2/3) and their confluence with the protocerebrum (PRT) of Jianfengia. The silver-proteinate section of an extant branchiopod crustacean (Triops, lower left) matches the circum-esophageal nerves and the convergence of segments T1-T3 as a syngan- glion. As in Branchiopoda,the Jianfengia deutocerebrum (Deu) is split in half:each half flanks the side of the esophageal foramen. The root of the branchiopod antennular nerve (RANN) corresponds to the root of the Jianfengia great appen- dage nerve (RGAN). The fossil ocellar nerves (OCN) are identified as originating from the ocelli of the anterior sclerite OC (ASC). The paired labral nerves and ganglia (Lab) occupy the same location as in extant pancrustaceans and in Leanchoiliidae, indicating an ancient origin3,24,55,56. b Annotated interpretive recon- struction of the cephalic area of J. multisegmentalis. Abbreviations: Tri tritocerebrum, GA great appendage, OC ocelli, ASC anterior sclerite, ON optic neuropil, CE+re compound eye+retina, PRS prosocerebral domain, PRT protocerebral domain. c Idealized reconstruction of whole animal based on specimens YKLP11117, YKLP11367 and YKLP17299. Segmental ganglia have not been resolved caudal to T3. Those shown are hypothetical, based on documented examples in other euarthropods24. Trunk appendages are biramous;pairs beneath the carapace have 5-7 articles, the rest have 10, except the last few.	Fig. 4 | Interpretive reconstruction of Jianfengia multisegmentalis. a Fossil neural traces on the right (blue; scale bar = 0.5 mm) align with arrangements of extant eucrustacean cerebral neuropils (anti-silver-proteinate preparations on left). Optic neuropils of the malacostracan Astacus astacus (Rabbit,polyclonal a-Tubulin, Abcam RRID:AB_301787) match the three nested optic neuropils (ON1-ON2/3) and their confluence with the protocerebrum (PRT) of Jianfengia. The silver-proteinate section of an extant branchiopod crustacean (Triops, lower left) matches the circum-esophageal nerves and the convergence of segments T1-T3 as a syngan- glion. As in Branchiopoda,the Jianfengia deutocerebrum (Deu) is split in half:each half flanks the side of the esophageal foramen. The root of the branchiopod antennular nerve (RANN) corresponds to the root of the Jianfengia great appen- dage nerve (RGAN). The fossil ocellar nerves (OCN) are identified as originating from the ocelli of the anterior sclerite OC (ASC). The paired labral nerves and ganglia (Lab) occupy the same location as in extant pancrustaceans and in Leanchoiliidae, indicating an ancient origin3,24,55,56. b Annotated interpretive recon- struction of the cephalic area of J. multisegmentalis. Abbreviations: Tri tritocerebrum, GA great appendage, OC ocelli, ASC anterior sclerite, ON optic neuropil, CE+re compound eye+retina, PRS prosocerebral domain, PRT protocerebral domain. c Idealized reconstruction of whole animal based on specimens YKLP11117, YKLP11367 and YKLP17299. Segmental ganglia have not been resolved caudal to T3. Those shown are hypothetical, based on documented examples in other euarthropods24. Trunk appendages are biramous;pairs beneath the carapace have 5-7 articles, the rest have 10, except the last few.	2025-08-28	Strausfeld, Nicholas J.;Andrew, David R.;Hou, Xianguang;Hirth, Frank		Zenodo	biologists	Strausfeld, Nicholas J.;Andrew, David R.;Hou, Xianguang;Hirth, Frank			
D864325A597B03547C1C4A726641F960.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/17038541/files/figure.png	https://doi.org/10.5281/zenodo.17038541	Fig. 5 | Phylogenetic inferences reveal Jianfengia multisegmentalis as sister to total Mandibulata. (See also Supplementary Fig. 4). Strict consensus tree from maximum parsimony analysis under equal character weights identifies J.multisegmentalis as basal sister group and ancestral to all Mandibulata. This tree is the result of two most parsimonious trees (tree length= 221 steps; CI = 0.54;RI = 0.78), with an unresolved polytomy at the base of the pancrustacean clade. Pyc. Pycnogonida, Xiphos. Xiphosura, ✝ = extinct taxon.	Fig. 5 | Phylogenetic inferences reveal Jianfengia multisegmentalis as sister to total Mandibulata. (See also Supplementary Fig. 4). Strict consensus tree from maximum parsimony analysis under equal character weights identifies J.multisegmentalis as basal sister group and ancestral to all Mandibulata. This tree is the result of two most parsimonious trees (tree length= 221 steps; CI = 0.54;RI = 0.78), with an unresolved polytomy at the base of the pancrustacean clade. Pyc. Pycnogonida, Xiphos. Xiphosura, ✝ = extinct taxon.	2025-08-28	Strausfeld, Nicholas J.;Andrew, David R.;Hou, Xianguang;Hirth, Frank		Zenodo	biologists	Strausfeld, Nicholas J.;Andrew, David R.;Hou, Xianguang;Hirth, Frank			
