The are many allopolyploid plant species, that is, polyploid species with chromosomes derived from two or more diverged taxa. For example, common wheat, Triticum aestivum, is an allohexaploid carrying chromosomes from two separate ancestor species, einkorn wheat Triticum urartu, and a goatgrass, Aegilops speltoides. (Note than two ancestor species are not even in the same genus.) In general, the taxonomy of wheat is an unsettled mess, with three different ancestral species (Triticum urartu, Aegilops speltoides and Aegilops tauschii, multiple genome duplication and hybridization events, and disagreement between traditional morphological taxonomy and molecular taxonomy. (Note how the table in the Wikipedia article needs to have separate columns for species recognized by traditionalist morphology-based phylogeny, and species recognized by ultra-modern molecular phylogeny.)
In the genus Brassica of cruciferous vegetables we find a well-known relationship between six species, three ancestral diploid species, and three derived allotetraploid species. Note that all six species are important crops:
The so-called triangle of U showing the relationship between three ancestral and three allotetraploid species in the genus Brassica. Brassica nigra is the black mustard; Brassica oleracea is cabbage, broccoli, cauliflower and so on; Brassica rapa is turnips; Brassica juncea is the Indian mustard; Brassica napus is rapeseed and rutabaga or Swedish turnips; and Brassica carinata is the Ethiopian mustard. As for U himself, he was a Korean botanist, Woo Jang-choon, who, during most of his life, lived under the rule of Imperial Japan and used the Japanified name Nagaharu U. Diagram by Adenosine, Nashville Monkey et al., available on Wikimedia under the Creative Commons Attribution-Share Alike 2.5 Generic license.
In animals, examples of species carrying genes originating in more than one ancestral species are rarer but they do exist.
One of the best studied cases is the genus Panthera of big cats, where four out of five extant species (the tiger, the leopard, the lion and the jaguar) have been found to carry genes originating in other species of the genus; for a nice diagram see Jordana Cepelewicz, "Interspecies Hybrids Play a Vital Role in Evolution", in Quanta Magazine, 24 August 2017.
Henrique V. Figueiró, Gang Li, Fernanda J. Trindade, et al. writing in Science Advances, have the following to say in their article "Genome-wide signatures of complex introgression and adaptive evolution in the big cats" (Science Advances, 19 Jul 2017, Vol. 3, no. 7, e1700299, DOI: 10.1126/sciadv.1700299):
The great cats of the genus Panthera comprise a recent radiation whose evolutionary history is poorly understood. [...] We observed pervasive genealogical discordance across Panthera genomes, caused by both incomplete lineage sorting and complex patterns of historical interspecific hybridization. We found [in jaguars] at least two genes (DOCK3 and COL4A5, both related to optic nerve development) bearing significant signatures of interspecies introgression and within-species positive selection. These findings indicate that post-speciation admixture has contributed genetic material that facilitated the adaptive evolution of big cat lineages.
The genus Panthera is a remarkable group to investigate these issues because it comprises five big cat species that arose from a recent and rapid diversification process. Understanding the history of their unique features [...] depends on resolving the underlying phylogeny of the Panthera clade, a task that has been notoriously difficult to accomplish. Recent analyses have indicated that genealogical discordance caused by both incomplete lineage sorting (ILS) and post-speciation admixture has contributed to produce such a complex system.
The lion lineage exhibited the most widespread signatures of ancient admixture, likely due to its broad historical range throughout much of the Holarctic region, overlapping with several congeneric species. These results considerably expand the recent evidence for hybridization between the snow leopard and the lion + leopard ancestor [...] and reveal a much more complex history of post-speciation admixture in this group than was previously appreciated.