Due to differences in morphology, ecology and biology, the phylogenesis of Coniferopsida and Taxaceae remains controversial, and the phylogenetic relationship of Pseudotaxus is yet to be confirmed. Three rDNA regions,...Due to differences in morphology, ecology and biology, the phylogenesis of Coniferopsida and Taxaceae remains controversial, and the phylogenetic relationship of Pseudotaxus is yet to be confirmed. Three rDNA regions, ITS1, 5.8S rDNA, and ITS2, were prepared for 77 species belonging to seven families of Coniferopsida, including Taxaceae. Maximum parsimony(MP)and Neighbor-joining(NJ) analyses were performed. Results showed that:(1) the Coniferopsida species formed three branches:(Taxaceae, Cephalotaxaceae, Cupressaceae, Taxodiaceae),(Araucariaceae, Podocarpaceae), and(Pinaceae);(2) Taxaceae included Taxus, Pseudotaxus, Amentotaxus, and Torreya; and(3) Pseudotaxus belonged to Taxaceae, with a support rate of 97%in MP analyses and 99% in NJ analyses.展开更多
记述甘肃酒泉盆地早白垩世地层中发现的两种掌鳞杉科植物化石Pseudofrenelopsis dalatzensis(ChowetTsao,1977)Cao ex Zhou和P.gansuensissp.nov.。其中,归入P.dalatzensis的标本无论是小枝形态还是表皮构造都与产于吉林延吉盆地大砬子...记述甘肃酒泉盆地早白垩世地层中发现的两种掌鳞杉科植物化石Pseudofrenelopsis dalatzensis(ChowetTsao,1977)Cao ex Zhou和P.gansuensissp.nov.。其中,归入P.dalatzensis的标本无论是小枝形态还是表皮构造都与产于吉林延吉盆地大砬子组的模式标本一致。定为新种的标本小枝较粗,可能只有一枚叶;节间角质层厚25—30μm,表面没有乳突和表皮毛,气孔器和表皮细胞均规则成行排列;气孔器圆形或椭圆形,较大,整体下陷。副卫细胞通常5—7个,少数可达8—9个。保卫细胞仅部分保存。已发现的Pseudofrenelopsis均分布于北半球,时代限于早白垩世,且多为早白垩世晚期,其中P.dalatzensis在模式标本产地与丰富的被子植物共生,应为早白垩世Aptian到Albian期。该种在酒泉盆地中沟组的出现说明该组的时代最高可到Aptian或Albian期。已有资料还表明,Pseudofrenelopsis主要生活于有季节变化、盐度较高或较干旱的环境中,这与酒泉盆地早白垩世沉积物和其他门类的化石所指示的环境特征相符合。展开更多
文摘Due to differences in morphology, ecology and biology, the phylogenesis of Coniferopsida and Taxaceae remains controversial, and the phylogenetic relationship of Pseudotaxus is yet to be confirmed. Three rDNA regions, ITS1, 5.8S rDNA, and ITS2, were prepared for 77 species belonging to seven families of Coniferopsida, including Taxaceae. Maximum parsimony(MP)and Neighbor-joining(NJ) analyses were performed. Results showed that:(1) the Coniferopsida species formed three branches:(Taxaceae, Cephalotaxaceae, Cupressaceae, Taxodiaceae),(Araucariaceae, Podocarpaceae), and(Pinaceae);(2) Taxaceae included Taxus, Pseudotaxus, Amentotaxus, and Torreya; and(3) Pseudotaxus belonged to Taxaceae, with a support rate of 97%in MP analyses and 99% in NJ analyses.
文摘记述甘肃酒泉盆地早白垩世地层中发现的两种掌鳞杉科植物化石Pseudofrenelopsis dalatzensis(ChowetTsao,1977)Cao ex Zhou和P.gansuensissp.nov.。其中,归入P.dalatzensis的标本无论是小枝形态还是表皮构造都与产于吉林延吉盆地大砬子组的模式标本一致。定为新种的标本小枝较粗,可能只有一枚叶;节间角质层厚25—30μm,表面没有乳突和表皮毛,气孔器和表皮细胞均规则成行排列;气孔器圆形或椭圆形,较大,整体下陷。副卫细胞通常5—7个,少数可达8—9个。保卫细胞仅部分保存。已发现的Pseudofrenelopsis均分布于北半球,时代限于早白垩世,且多为早白垩世晚期,其中P.dalatzensis在模式标本产地与丰富的被子植物共生,应为早白垩世Aptian到Albian期。该种在酒泉盆地中沟组的出现说明该组的时代最高可到Aptian或Albian期。已有资料还表明,Pseudofrenelopsis主要生活于有季节变化、盐度较高或较干旱的环境中,这与酒泉盆地早白垩世沉积物和其他门类的化石所指示的环境特征相符合。
