辽西北票市四合屯及周边地区赋存长毛恐龙及早期鸟类化石的地层时代,存在晚侏罗世、早白垩世和晚侏罗世-早白垩世多种观点。同样,同位素年龄数据亦存在很大差异。作者曾报道四合屯含脊椎动物化石层位的地层综合剖面第6层所夹YL31凝灰岩中锆石的U-Pb年龄为125.2±0.9 Ma,并指出四合屯脊椎动物生存时代属早白垩世。本文报道两组 Ar-Ar定年数据,作为这一观点的又一新的证据。YL29玄武安山岩的层位属综合地层剖面第2层下部,它的K-Ar年龄是129.0±2.6 Ma。此样品的Ar-Ar阶段加热实验给出一条平坦的年龄谱线,其坪年龄是128.2±0.8Ma,对应的39Ar析出量达90％以上;15个阶段的总气体年龄为128.4±1.4 Ma;相关性很好的Ar-Ar等时线给出的年龄是128.4±0.2 Ma。YL30辉绿岩侵入到综合地层剖面5-9层,其Ar-Ar年龄谱也呈平坦状,坪年龄是122.3±0.5 Ma,对应的39Ar析出量高达93％以上;12个阶段的总气体年龄为122.1±1.2 Ma;相关性很好的Ar-Ar等时线给出的年龄是121.8±1.3Ma。国际上关于晚侏罗世～早白垩世界线年龄一直存有争议,其观点主要有135Ma和144Ma两种方案,中国年代学工作者倾向性135±5Ma。无论采用哪种方案,四合屯脊椎动物生存时代均属早白垩世。 There are many views of Late Jurassic, Early Cretaceous and Late Jurassic-Early Cretaceous in the stratigraphic era of Sihengtun and its surrounding areas where the hairy dinosaurs and early bird fossils are hosted. Similarly, isotopic age data also vary widely. The author has reported that the U-Pb age of zircons in the YL31 tuff, which is located in the sixth strata of the stratigraphic integrated profile of the stratigraphic layer of the Tuotun vertebrate fossils, is 125.2 ± 0.9 Ma. It is also pointed out that the age of the Sihetun vertebrate is of the Early Cretaceous . This article reports two sets of Ar-Ar dating data as another new evidence from this perspective. The YL29 basaltic andesite belongs to the lower part of the second layer of the integrated stratigraphic section, and its K-Ar age is 129.0 ± 2.6 Ma. The Ar-Ar stage heating experiment of this sample gives a flat age line with a plateau age of 128.2 ± 0.8Ma and a corresponding 39Ar precipitation rate of over 90%. The total gas ages at 15 stages are 128.4 ± 1.4 Ma; The well-correlated Ar-Ar isochron gives the age of 128.4 ± 0.2 Ma. The YL30 diabase intrudes into layers 5-9 in the integrated stratigraphic section, and its Ar-Ar age spectrum is also flat. The Ping age is 122.3 ± 0.5 Ma and the corresponding 39Ar precipitation is as high as 93%. The total gas ages of 12 stages Was 122.1 ± 1.2 Ma; the well-correlated Ar-Ar isochron gives the age of 121.8 ± 1.3Ma. Internationally, there is controversy over the age line of the Late Jurassic to Early Cretaceous. The views are mainly 135Ma and 144Ma. The Chinese geochronology workers tend to be 135 ± 5Ma. No matter what kind of program, Sihetun vertebrate survival times are Early Cretaceous.